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Environmental Science Table of Contents
37
Lab 3
Biodiversity
Biodiversity
Concepts to Explore
• Biodiversity
• Species diversity
• Ecosystem diversity
• Genetic diversity
• Natural selection
• Extinction
Introduction
Biodiversity, short for biological diversity, includes the genetic
variation between all organisms, species, and
populations, and all of their complex communities and
ecosystems. It also reflects to the interrelatedness of
genes, species, and ecosystems and their interactions with the
environment. Biodiversity is not evenly distrib-
uted across the globe; rather, it varies greatly and even varies
within regions. It is partially ruled by climate,
whereas tropical regions can support more species than a polar
climate. In whole, biodiversity represents
variation within three levels:
• Species diversity
• Ecosystem diversity
• Genetic diversity
It should be noted that diversity at one of these levels may
not correspond with diversity within other levels. The degree
of biodiversity, and thus the health of an ecosystem, is im-
pacted when any part of that ecosystem becomes endan-
gered or extinct.
The term species refers to a group of similar organisms that
reproduce among themselves. Species diversity refers to
the variation within and between populations of species, as
well as between different species. Sexual reproduction criti-
cally contributes to the variation within species. For exam-
ple, a pea plant that is cross-fertilized with another pea plant
can produce offspring with four different looks! This genetic
mixing creates the diversity seen today.
Figure 1: There are more than 32,000 species of
fish – more than any other vertebrate!
39
Biodiversity
Ecosystem diversity examines the different habitats, biological
communities, and ecological processes in
the biosphere, as well as variation within an individual
ecosystem. The differences in rainforests and deserts
represent the variation between ecosystems. The physical
characteristics that determine ecosystem diversity
are complex, and include biotic and abiotic factors.
? Did You Know...
A present day example of natural
selection can be seen in the cray-
fish population. The British crayfish
are crustaceans that live in rivers in
England. The American crayfish
was introduced to the same bodies
of water that were already populat-
ed by the British crayfish. The
American crayfish are larger, more
aggressive and carry an infection
that kills British crayfish but to
which they are immune. As a re-
sult, the British crayfish are de-
creasing in number and are ex-
pected to become extinct in Britain
within the next 50 years. Thus, the
American crayfish have a genetic
variation that gives them an ad-
vantage over the British crayfish to
survive and reproduce.
The variation of genes within individual organisms is genetic
diversity.
This can be measured within a species as well as between
species. It
plays an important role in survival and adaptability of
organisms to
changing environments.
Diversity is also influenced by natural selection, the key
mechanism of
evolution. The process of natural selection describes
competition be-
tween individual species for resources such as food and space
(habitat). Genetic variations among species provide an
advantage over
other species if those variations result in an ability to survive
and repro-
duce more effectively.
Evidence that supports the theory of natural selection include
the fossil
record of change in earlier species, the chemical and anatomical
simi-
larities of related life forms, the geographical distribution of
related spe-
cies, and the recorded genetic changes in living organisms over
many
generations. Take for example, homologous structures among
different
species, such as the wing of a bird and the forearm of a human.
These
structures provide evidence that embryologically similar
structures can
give rise to different functions based on the needs of the
organism.
Note that natural selection does not try to explain the origin of
life but
rather the later evolution of organisms over time.
Biodiversity is important to the process of evolution because it
provides
the framework on top of which natural selection can occur. As
dis-
cussed above, natural selection determines the genetic fitness,
an or-
ganism's genetic contribution to the next generation, of an
organism.
Natural selection occurs by selecting one trait as "more
advantageous" in a certain environment than anoth-
er. The root of this selection is biodiversity.
Species extinction is not new; species have been evolving and
dying out since life began. Now, however,
species extinction is occurring at an alarming rate, almost
entirely as a direct result of human activities. Sci-
40
Biodiversity
entists recognize five major mass extinctions in the Earth’s
history. The extinctions are measured in terms of
large groups of related species, called families. The five mass
extinction episodes occurred because of major
changes in the prevailing ecological conditions brought about
by climate change, cataclysmic volcanic erup-
tions, or collisions with giant meteors. The sixth mass
extinction appears to be in progress now, and the pri-
mary cause is environmental change brought about by human
activities. Some examples of species on the
“endangered” list are the ivory billed woodpecker, amur
leopard, javan rhinoceros, northern great whale,
mountain gorilla, and the leatherback sea turtle.
Figure 2: The amur leopard is at risk of extinction.
Loss of an individual species can have various effects on the
remaining species in an ecosystem. These ef-
fects depend upon the how important the species is in the
ecosystem. Individual species and ecosystems
have evolved over millions of years into a complex
interdependence. If you remove enough of the key spe-
cies on which the framework is based, then the whole ecosystem
may be in danger of collapsing. Regardless
of a species’ place in the ecosystem, it is important for humans
to take care of the world around us. As peo-
ple become more aware of how their actions impact all living
things they can make adjustments in an effort to
preserve life on all levels.
41
Biodiversity
There are many activities that humans take part in that impact
the environment and biodiversity. The exhaust
from automobile and aircraft travel as well as smoke stacks
from industrial plants are the leading causes of air
pollution, which can have harmful effects on natural resources
and organisms. Two other important factors
which can have an effect on biodiversity are overpopulation and
affluence. Overpopulation means that there
are more people than resources to meet their needs. As people
become more affluent there is an increase in
per capita resource utilization. All of these factors contribute to
overharvesting, habitat degradation, and in-
creased pollution which threaten biodiversity.
42
Biodiversity
Demonstration 1: Interdependence of Species
In this lab, you will use the information provided above to
demonstrate how the presence or absence of one
species can affect the others in an ecosystem. Follow the
procedure below to complete Demonstration 1 on
the interdependence of species.
Materials
5 different colored beads:
White bead represents lichen
Orange bead represents trees
Red bead represents flowers
Yellow bead represents bees
Blue bead represents humans
Lichens
Lichens play a part in the creation of soils from which plants
can obtain nutrients. Like all living
organisms, lichens need nutrients and energy to grow. Nutrients
may be obtained from the air
(including dust), water, and from the substrate organisms grows
on. They obtain energy through
photosynthesis, which is the role of the algal partner. They may
also be incidentally fertilized by
bird and insect dung.
Trees
Most trees, flowers and plants depend on soil for food
(nutrients). Fruiting trees depend on bees
as one means of pollination.
Flowers
Forest flowers and plants depend on trees for shade and wind
protection as well as soils for nutri-
ents.
Bees
Bees depend on flowering plants and trees for food.
Humans
Humans depend upon bees for honey and more importantly for
fruit from trees they pollinate.
43
Biodiversity
Procedure
1. Download the Week 3 Lab Reporting Form from the course
instructions. As you conduct the demonstra-
tion and the experiment, record any hypotheses, observations,
and data on that form.
2. Place all of the beads in a bag.
3. Randomly choose 4 beads from the bag.
4. Identify each bead by the color code in the materials box.
5. Record which species is missing in Table 1 on the Week 3
Lab Reporting Form.
6. Repeat this process 3 more times (or until 3 different beads
are taken out of the diagram). Be sure to rec-
ord which species is missing from each round in Table 1 and
answer the Post-Lab questions on the Week
3 Lab Reporting Form.
Experiment 1: Diversity of Plants
Variations in growing conditions, climate, and numerous other
factors can alter the biodiversity of an ecosys-
tem. As such, biodiversity is often utilized as an indicator of
ecosystem health. In this experiment, you will
grow a sample of seeds under two different conditions. Follow
the procedure below to complete Experiment 1
on the diversity of plants.
Materials
Seed mixture (zinnia, marigold, morning glory,
cosmos, and ryegrass)
Potting soil
(2) 5.5 x 3.5 in Peat pots
10 mL Graduated cylinder
*Water
*You must provide
Procedure
1. Read through the Experiment 1 procedure and then record
your hypothesis on the biodiversity of seeds
grown under two separate conditions on the Week 3 Lab
Reporting Form.
2. Fill your pots loosely with soil until the soil is approximately
1 inch from the top.
3. Pour approximately 40 mL of tap water into your pots (less if
the soil becomes very wet).
44
Biodiversity
4. Lightly scatter your seeds on top of the soil in each
container. This should be a random assignment of
seeds to each pot.
5. Press each seed down about ½ inch into the soil.
6. Place one pot in a sunny, indoor location (on a window sill
that receives sunlight) and the second pot in a
shaded, indoor location (away from all windows, this pot should
not be placed in the dark, just away from
direct sunlight).
7. Observe and water your seeds every day until you see them
grow. These seeds will germinate quickly (3
- 7 days).
8. Complete Table 2 on the Week 3 Lab Reporting Form after
approximately 1 - 2 weeks (or when you see
a reasonable amount of plant growth in the peat pot) and answer
all Post-Lab Questions on the Week 3
Lab Reporting Form. Table 3 (provided on the following page)
provides pictures of the germinated seeds
to help you determine when you should begin entering data, and
what each plant looks like.
45
Weather and Climate Change
Table 3: Picture and Description of Seedlings Grown from Seed
Mixture
Species Observed Picture Description
Zinnia
Short stems with dark green,
rounded leaves
Marigold
Stems are shorter than cosmos
with long skinny leaves (but wid-
er than the cosmos leaves) with
rounded tips
Morning Glory
Tall stems with elephant ear
shaped leaves
Cosmos
Tall stems with long, pointed
leaflets; a lighter green leaf com-
pared to the marigold
Ryegrass
Long, skinny strands of green
grass
46
Appendix
Good Lab Techniques
Good Lab Techniques
Good Laboratory Techniques
Science labs, whether at universities or in your home, are places
of adventure and discovery. One of the first
things scientists learn is how exciting experiments can be.
However, they must also realize science can be
dangerous without some instruction on good laboratory
practices.
• Read the protocol thoroughly before starting any new
experiment.
You should be familiar with the action required every step of
the
way.
• Keep all work spaces free from clutter and dirty dishes.
• Read the labels on all chemicals, and note the chemical safety
rating
on each container. Read all Material Safety Data Sheets
(provided
on www.eScienceLabs.com).
• Thoroughly rinse lab ware (test tubes, beakers, etc.) between
experi-
ments. To do so, wash with a soap and hot water solution using
a
bottle brush to scrub. Rinse completely at least four times. Let
air
dry
• Use a new pipet for each chemical dispensed.
• Wipe up any chemical spills immediately. Check MSDSs for
special
handling instructions (provided on www.eScienceLabs.com).
• Use test tube caps or stoppers to cover test tubes when shaking
or
mixing – not your finger!
A B C
Figure 1: A underpad will
prevent any spilled liquids
from contaminating the sur-
face you work on.
Figure 2: Special measuring tools in make experimentation
easier and more accu- rate in
the lab. A shows a beaker, B graduated cylinders, and C test
tubes in a test tube rack.
67
Good Lab Techniques
• When preparing a solution, refer to a protocol for any specific
instructions on preparation. Weigh out the desired amount of
chemicals, and transfer to a beaker or graduated cylinder.
Add LESS than the required amount of water. Swirl or stir to
dissolve the chemical (you can also pour the solution back
and forth between two test tubes), and once dissolved, trans-
fer to a graduated cylinder and add the required amount of
liquid to achieve the final volume.
• A molar solution is one in which one liter (1L) of solution
con-
tains the number of grams equal to its molecular weight.
For example:
1M = 110 g CaCl x 110 g CaCl/mol CaCl
(The formula weight of CaCl is 110 g/mol)
Figure 3: Disposable pipettes aid in ac-
curate measuring of small volumes of
liquids. It is important to use a new pi-
pette for each chemical to avoid con-
tamination.
• A percent solution can be prepared by percentage of weight of
chemical to 100ml of solvent (w/v) , or
volume of chemical in 100ml of solvent (v/v).
For example:
20 g NaCl + 80 mL H2O = 20% w/v NaCl solution
• Concentrated solutions, such as 10X, or ten times the normal
strength, are diluted such that the final
concentration of the solution is 1X.
For example:
To make a 100 mL solution of 1X TBE from a 10X solution:
10 mL 10X TBE + 90 mL water = 100ml 1X TBE
• Always read the MSDS before disposing of a chemical to
insure it does not require extra measures.
(provided on www.eScienceLabs.com)
• Avoid prolonged exposure of chemicals to direct sunlight and
extreme temperatures. Immediately se-
cure the lid of a chemical after use.
• Prepare a dilution using the following equation:
c1v1 = c2v2
Where c1 is the concentration of the original solution, v1 is the
volume of the original solution, and
c2 and v2 are the corresponding concentration and volume of
the final solution. Since you know c1,
68
Good Lab Techniques
c2, and v2, you solve for v1 to figure out how much of the
original solution is needed to make a cer-
tain volume of a diluted concentration.
• If you are ever required to smell a chemical, always waft a gas
toward you, as shown in the figure
below.. This means to wave your hand over the chemical
towards you. Never directly smell a
chemical. Never smell a gas that is toxic or otherwise
dangerous.
• Use only the chemicals needed for the activity.
• Keep lids closed when a chemical is not being used.
• When diluting an acid, always slowly pour the acid into the
water. Never pour water into an acid,
as this could cause both splashing and/or an explosion.
• Never return excess chemical back to the original bottle. This
can contaminate the chemical sup-
ply.
• Be careful not to interchange lids between different chemical
bottles.
• When pouring a chemical, always hold the lid of the chemical
bottle between your fingers. Never
lay the lid down on a surface. This can contaminate the
chemical supply.
• When using knives or blades, always cut away from yourself.
69
© 2012 eScience Labs, LLC - All rights reserved
68
Lab 3Concepts to ExploreIntroductionDemonstration 1:
Interdependence of
SpeciesLichensMaterialsProcedureAppendixA B C© 2012
eScience Labs, LLC - All rights reserved
Lab 2 – Water Quality and Contamination
Experiment 1: Effects of Groundwater Contamination
Table 1: Water Observations (Smell, Color, Etc.)
Beaker
Observations
1
2
3
4
5
6
7
8
POST LAB QUESTIONS
1. Develop hypotheses on the ability of oil, vinegar, and laundry
detergent to contaminate groundwater.
a. Oil hypothesis =
b. Vinegar hypothesis =
c. Laundry detergent hypothesis =
2. Based on the results of your experiment, would you reject or
accept each hypothesis that you produced in question 1?
Explain how you determined this.
a. Oil hypothesis accept/reject =
b. Vinegar hypothesis accept/reject =
c. Laundry detergent hypothesis accept/reject =
3. What affects did each of the contaminants have on the water
in the experiment? Which contaminant seemed to have the most
potent effect on the water?
Answer =
4. Using at least 1 scholarly source, discuss what type of affects
these contaminants (oil, vinegar, detergent) might have on a
town’s water source and the people who drank the water?
Answer =
5. Describe what type of human activity would cause
contaminants like oil, acid and detergents to flow into the water
supply? Additionally, what other items within your house do
you believe could contaminate the water supply if you were to
dump them onto the ground?
Answer =
Experiment 2: Water Treatment
POST LAB QUESTIONS
1. Develop a hypothesis on the ability of your filtration
technique to remove contaminants.
Hypothesis =
2. Based on the results of your experiment, would you reject or
accept the hypothesis that you produced in question 1? Explain
how you determined this.
Accept/Reject =
3. What are the differences in color, smell, visibility, etc.
between the “contaminated” water and the “treated” water?
Answer =
4. From the introduction to this lab, you know that there are
typically five steps involved in the water treatment process.
Identify the processes (e.g., coagulation) that were used in this
lab and describe how they were performed.
Answer =
Experiment 3: Drinking Water Quality
Table 2: Ammonia Test Results
Water Sample
Test Results
Tap Water
Dasani® Bottled Water
Fiji® Bottled Water
Table 3: Chloride Test Results
Water Sample
Test Results
Tap Water
Dasani® Bottled Water
Fiji® Bottled Water
Table 4: 4 in 1 Test Results
Water Sample
pH
Total Alkalinity
Total Chlorine
Total Hardness
Tap Water
Dasani® Bottled Water
Fiji® Bottled Water
Table 5: Phosphate Test Results
Water Sample
Test Results
Tap Water
Dasani® Bottled Water
Fiji® Bottled Water
Table 6: Iron Test Results
Water Sample
Test Results
Tap Water
Dasani® Bottled Water
Fiji® Bottled Water
POST LAB QUESTIONS
1. Develop a hypothesis on which water source you believe will
contain the most and least contaminants.
Hypothesis =
2. Based on the results of your experiment, would you reject or
accept the hypothesis that you produced in question 1? Explain
how you determined this.
Accept/reject =
3. Based on the results of your experiment, what major
differences, if any, do you notice between the Dasani, Fiji, and
tap water?
Answer =
4. Based on your results, do you believe that bottled water is
worth the price? Why or why not?
Answer =
*NOTE – Do not forget to go to Lab 3: Biodiversity, and
complete “Experiment 1: Diversity of Plants” steps 1 through
6. Steps 1 through 6 need to be completed in order to be
prepared for Week Three, however, results for this experiment
will not be calculated until next week. Thus, while nothing is to
be handed in for this experiment until the end of Week Three
you must plant the seeds this week to ensure that you can
complete week 3 on time.
References
Any sources utilized should be listed here.
© eScience Labs, 2013
Environmental Science Table of Contents
21
Lab 2
Water Quality and Contamination
Water Quality and Contamination
Concepts to Explore
• Usable water
• Ground water
• Surface water
• Ground water contaminates
• Water treatment
• Drinking water quality
Figure 1: At any given moment, 97% of the planet’s water is in
the oceans. Only a small fraction
of the remaining freshwater is usable by humans, underscoring
the importance of treating our
water supplies with care.
Introduction
It is no secret that water is one of the most valuable resources
on planet Earth. Every plant and animal re-
quires water to survive, not only for drinking, but also for food
production, shelter creation and many other ne-
cessities. Water has also played a major role in transforming the
earth’s surface into the varied topography we
see today.
While more than 70% of our planet is covered in water, only a
small percent of this water is usable freshwater.
The other 99% of the water is composed primarily of salt water,
with a small percentage being composed of
23
Water Quality and Contamination
glaciers. Due to the high costs involved in transforming salt
water into freshwater, the Earth’s population sur-
vives off the less than 1% of freshwater available. Humans
obtain freshwater from either surface water or
groundwater.
Surface water is the water that collects on the ground as a result
of precipitation. The water that does not
evaporate back into the atmosphere or infiltrate into the ground
is typically collected in rivers, lakes, reser-
voirs, and other bodies of water and is easily accessible.
Precipitation
Precipitation Precipitation
Cloud formation
Transpiration
Evaporation
Evaporation
Groundwater
Figure 2: Water is a renewable source, purified and
delivered across the planet by the hydrological cycle.
Groundwater, on the other hand, is precisely as the name
suggests; water located underneath the ground.
This water is stored in pores, fractures and other spaces within
the soil and rock underneath the ground’s sur-
face. Precipitation, along with snowmelt, infiltrates through the
ground and accumulates in available under-
ground spaces.
Aquifers are areas in which water collects in sand, gravel, or
permeable rock from which it can be extracted
for usable freshwater. The depth of aquifers vary from less than
50 feet to well over 1,500 feet below the sur-
face of the ground. The water within an aquifer typically does
not flow through as it would through a river or
stream, but instead soaks into the underground material, similar
to a sponge. As aquifers are depleted by hu-
man use, they are also recharged from precipitation seeping into
the ground and restoring the water level.
However, many times the recharge of the aquifers does not
equal the amount of water that has been extract-
ed. If that cycle continues, the aquifer will eventually dry up
and will no longer be a viable source of groundwa-
ter.
24
Water Quality and Contamination
Water is the only substance
that is found naturally in
three forms: solid, liquid,
and gas
If the entire world’s supply
of water could fit into a one-
gallon jug, the fresh water
available to use would equal
less than one tablespoon
Approximately 66% of the
human body consists of wa-
ter - it exists within every
organ and is essential for its
function
While the water that precipitates down in the form of rain is
relatively pure, it does not take long for water to
pick up contaminants. There are natural, animal, and human-
made sources of water pollutants. They can
travel freely from one location to another via streams, rivers,
and even groundwater. Pollutants can also trav-
el from land or air into the water. Groundwater contamination
most often occurs when human-made products
such as motor oil, gasoline, acidic chemicals and other
substances leak into aquifers and other groundwater
storage areas. The most common source of contaminants come
from leaking storage tanks, poorly main-
tained landfills, and septic tanks, hazardous waste sites and the
common use of chemicals such as pesti-
cides and road salts.
The dangers of consuming contaminated water are
high. Many deadly diseases, poisons and toxins can
reside in the contaminated water supplies and severely
affect the health of those who drink the water. It is also
believed that an increased risk of cancer may result
from ingesting contaminated groundwater.
With the many contaminants that can infiltrate our wa-
ter supply, it is crucial that there be a thorough water
treatment plan in place to purify the water and make it
drinkable. While each municipality has its own water
treatment facility, the process is much the same at each
location.
Figure 3: Sedimentation tanks, such as those shown
above, are used to settle the sludge and remove oils
and fats in sewage. This step can remove a good por-
tion of the biological oxygen demand from the sew-
age, a key step before progressing with the treat-
ments and eventually releasing into the ground or
body of water.
25
Water Quality and Contamination
The process begins with aeration in which air is added to the
water to let trapped gases escape while increasing the
amount of oxygen within the water. The next step is called
coagulation or flocculation, in which chemicals, such as filter
alum, are added to the incoming water and then stirred vigor-
ously in a powerful mixer. The alum causes compounds such
as carbonates and hydroxides to form tiny, sticky clumps
called floc that attract dirt and other small particles. When the
sticky clumps combine with the dirt they become heavy and
sink to the bottom. In the next step, known as sedimentation,
the heavy particles that sank to the bottom during coagula-
tion are separated out and the remaining water is sent on to
filtration. During filtration, the water passes through filters
made of layers of sand, charcoal, gravel and pebbles that
help filter out the smaller particles that have passed through
until this point. The last step is called disinfection in which
chlorine and/or other disinfectants are added to kill any bac-
Figure 4: Fresh water is essen-
tial to humans and other land-
based life. Contaminated water
must be treated before it can be
released into the water supply.
teria that may still be in the water. At this point the water is
stored until it is distributed through
various pipes to city residents and businesses.
After the water goes through the treatment process, it must also
pass the guidelines stated in
the Safe Drinking Water Act in which various components are
tested to ensure that the quality
of the water is sufficient for drinking. There are currently over
65 contaminants that must be
monitored and maintained on a regular basis to keep local
drinking water safe for the public.
Some of these chemical regulations include lead, chromium,
selenium and arsenic. Other com-
ponents such as smell, color, pH and metals are also monitored
to ensure residents are provid-
ed clean and safe drinking water.
26
Water Quality and Contamination
Experiment 1: Effects of Groundwater Contamination
In this lab you will test the effects of common pollutants on
groundwater. When mixed with water, everyday
items such as laundry detergent, oil, and vinegar can alter the
color, smell, and taste of water. You have likely
observed these changes through everyday activities such as
adding laundry detergent to water in the washing
machine, or noticing oil within a puddle on the street. Many of
these chemicals end up dispersing throughout
our environment, and while soil bacteria can reduce many of
these contaminants, they may not be able to
stop them from reaching our groundwater sources located
beneath the soil. In Experiment 1 you will test the
ability of soil to remove oil, vinegar, and laundry detergent
from the environment before it reaches groundwa-
ter. Follow the procedure below to complete Experiment 1 on
the effects of groundwater contamination.
Materials
(8) 250 mL Beakers
Permanent marker
3 Wooden stir sticks
100 mL Graduated cylinder
10 mL Vegetable oil
10 mL Vinegar
10 mL Liquid laundry detergent
100 mL Beaker
240 mL Soil
Funnel
Cheesecloth
*Scissors
*Water
*You must provide
Procedure
1. Download the Week 2 Lab Reporting Form from the course
instructions. As you conduct all 3 experi-
ments, record hypotheses, observations, and data on that form.
2. Read through the Experiment 1 procedure and then record
your hypotheses on the ability of oil, vinegar,
and laundry detergent to contaminate groundwater on the Week
2 Lab Reporting Form. You should pro-
vide one hypothesis for each situation.
3. Use the permanent marker to label the beakers 1 - 8.
4. Set Beakers 5 - 8 aside. Fill Beakers 1 - 4 with 100 mL of
water using your 100 mL graduated cylinder.
5. Record your observations of the water in Beaker 1 in Table 1
on the Week 2 Lab Reporting Form. Re-
member to use a safe wafting technique to smell the solutions.
27
Water Quality and Contamination
6. Add 10 mL of vegetable oil to Beaker 2. Mix thoroughly with
a wooden stir stick. Record your observations
of the water in Beaker 2 in Table 1 on your Week 2 Lab
Reporting Form. (Don’t forget to wash the gradu-
ated cylinder between use!)
7. Add 10 mL vinegar to beaker 3. Mix thoroughly with a
wooden stir stick. Record your observations of the
water in Beaker 3 in Table 1 on your Week 2 Lab Reporting
Form.
8. Add 10 mL of liquid laundry detergent to beaker 4. Mix
thoroughly with a wooden stir stick. Record your
observations of the water in Beaker 4 in Table 1 on your Week
2 Lab Reporting Form.
9. Cut your piece of cheesecloth into five different pieces
(reserve one piece for the next experiment). Fold
one piece of the cheesecloth so that you have a piece 4 layers
thick and big enough to line the funnel.
Place it inside the funnel.
10. Measure out 60 mL of soil using the 100 mL beaker and
place it into the cheesecloth-lined funnel.
11. Place the funnel inside Beaker 5.
12. Pour the contents of Beaker 1 (water) through the funnel so
that it filters into Beaker 5 for one minute.
Record your observations of the filtered water in the beaker in
Table 1 on your Week 2 Lab Reporting
Form.
13. Discard the cheesecloth and soil from the funnel.
14. Repeat Steps 9 - 13 for Beakers 2, 3, and 4 and complete the
Post-Lab questions on the Week 2 Lab Re-
porting Form. (Filter the contents of Beaker 2 into Beaker 6, the
contents of Beaker 3 into Beaker 7, and
the contents of Beaker 4 into Beaker 8).
28
Water Quality and Contamination
Experiment 2: Water Treatment
With the many pollutants that are added to our water supply
from daily human activity, it is important that we
have a way to filter our water to make it safe for drinking.
Wastewater treatment plants use sophisticated
techniques to make water potable. In Experiment 2, you will use
a similar technique to test the effectiveness
of one filtering method on the ability to purify contaminated
water. Follow the procedure below to complete
Experiment 2 on the effects of one method of water treatment.
Materials
100 mL Potting soil
(2) 250 mL Beakers
(2) 100 mL Beakers
100 mL Graduated cylinder
40 mL Sand
20 mL Activated charcoal
60 mL Gravel
1 Wooden stir stick
Alum
Funnel
Cheesecloth
Bleach
Stopwatch
*Water
*You must provide
Procedure
1. Read through the Experiment 2 procedure and then record
your hypothesis on the ability of your filtration
technique to remove contaminants on your Week 2 Lab
Reporting Form.
2. Add 100 mL of soil to the 250 mL beaker. Fill to the 200 mL
mark with water.
3. Pour the soil solution back and forth between the two 250 mL
beakers for a total of 15 times.
4. After the solution is created, pour 10 mL of the now
“contaminated” water into a clean 100 mL beaker.
This sample will be used to compare to the “treated” water at
the end of the filtration process.
5. Add 10 grams of alum (all of the contents in the bag you have
been given) to the 250 mL beaker contain-
ing the “contaminated” water. Slowly stir the mixture with a
wooden stir stick for 1-2 minutes. Let the so-
lution sit for 15 minutes.
6. In the meantime, rinse out the empty 250 mL beaker. Place
the funnel into the clean 250 mL beaker. Fold
a piece of cheesecloth so that you have a piece 4 layers thick
that is big enough to line the funnel. Place
29
Water Quality and Contamination
it inside the funnel.
7. Begin layering the funnel, starting by pouring 40 mL of sand
into the cheesecloth-lined funnel, then 20 mL
activated charcoal, then 40 mL gravel. Use a 100 mL beaker to
measure these amounts.
8. To solidify the filter, slowly pour clean tap water through the
filter until the funnel is full. Discard the rinse
water from the beaker and repeat four more times. Return the
funnel to the top of the beaker and let sit for
5 minutes before emptying the beaker and continuing the
experiment.
9. Now, without mixing up the current sediment in the
“contaminated” water jar, pour about 3/4 of the
“contaminated” water into the funnel. Let it filter through the
funnel into the beaker for 5 minutes.
10. Note the smell of the filtered water, comparing it to the 10
mL sample taken from the mixture in Step 3.
11. Remove the filter and add a few drops of bleach solution to
the filtered water within the beaker. Stir the
water and bleach combination slowly for about 1 minute.
12. The “contaminated” water has now been filtered. Compare
the newly created “treated” water with the 10
mL sample of the initial “contaminated” water and answer the
Post-Lab questions on the Week 2 Lab Re-
porting Form.
30
Water Quality and Contamination
Experiment 3: Drinking Water Quality
Bottled water is a billion dollar industry within the United
States alone. Still, various reports have shown that
many bottled water products contain the same chemical
contaminants as our tap water. In Experiment 3, you
will test the quality of two separate bottled waters and your tap
water by measuring a variety of chemical com-
ponents within the water. Follow the procedure below to
complete Experiment 3 on drinking water quality.
Materials
Dasani® bottled water
Fiji® bottled water
Ammonia test strips
Chloride test strips
4 in 1 test strips
Phosphate test strips
Iron test strips
(3) 250 mL Beakers
Permanent marker
Stopwatch
Parafilm®
Pipettes
(3) Foil packets of reducing powder
*Tap water
*You must provide
Procedure
1. Read through the Experiment 3 procedure and then record
your hypothesis on which water source you
believe will have the most and least contaminants on the Week
2 Lab Reporting Form.
2. Label three 250 mL beakers Tap Water, Dasani® and Fiji®.
Pour 100 mL of the each type of water into
the corresponding beakers.
Ammonia Test Strip
3. Locate the ammonia test strips. Begin by placing the test
strip into the tap water sample and vigorously
moving the strip up and down in the water for 30 seconds,
making sure that the pads on the test strip are
always submerged.
4. Remove the test strip from the water and shake off the excess
water.
5. Hold the test strip level, with the pad side up, for 30 seconds.
31
Water Quality and Contamination
6. Read the results by turning the test strip so the pads are
facing away from you. Compare the color of the
small pad to the color chart at the end of the lab. Record your
results in Table 2 on the Week 2 Lab Re-
porting Form.
7. Repeat the procedure for both Dasani® and Fiji|® bottled
water. Record your results for both in Table 2
on the Week 2 Lab Reporting Form.
Chloride Test Strip
8. Locate the chloride test strips. Begin by immersing all the
reaction zones (the pads) of the test strip in to
the tap water sample for 1 second.
9. Shake off the excess liquid from the test strip and after 1
minute, determine which color row the test strip
most noticeably coincides with on the color chart at the end of
the lab. Record your results in Table 3 on
the Week 2 Lab Reporting Form.
10. Repeat the procedure for both Dasani® and Fiji® Bottled
Water. Record your results for both in Table 3.
4 in 1 Test Strip
11. Locate the 4 in 1 test strips. Begin by dipping the test strip
in the tap water for 5 seconds with a gentle
back and forth motion.
12. Remove the test strip from the water and shake once,
briskly, to remove the excess water.
13. Wait 20 seconds and then using the color chart at the end of
this lab, match the test strip to the pH, Total
Alkalinity, Total Chlorine, and Total Hardness on the color
chart. Be sure to do all of the readings within
seconds of each other. Record your results in Table 4 on the
Week 2 Lab Reporting Form.
14. Repeat the procedure for both Dasani® and Fiji® Bottled
Water. Record your results for both in Table
4.
Phosphate Test Strip
15. Locate the phosphate test strips. Being by dipping the test
strip into the tap water for 5 seconds.
16. Remove the test strip from the water and hold horizontal,
with the pad side up, for 45 seconds. Do not
shake the excess water from the test strip.
32
Water Quality and Contamination
17. Compare the results on the pad of the test strip with the
color chart at the end of this lab. Record your
results in Table 5 on the Week 2 Lab Reporting Form.
18. Repeat the procedure for both Dasani® and Fiji® bottled
water. Record your results for both in Table 5.
Iron Test Strip
19. Locate the iron test strips. Begin by removing 70 mL of
water from each beaker and discarding it, leaving
a total of 30 mL within each of the three beakers.
20. Beginning with the tap water, open one foil packet and add
the powder contents to the beaker. Cover the
beaker with a piece of Parafilm® and shake the beaker
vigorously for 15 seconds.
21. Remove the Parafilm® and dip the test pad of the iron test
strip into the tap water sample, rapidly moving
it back and forth under the water for 5 seconds.
22. Remove the strip and shake the excess water off. After 10
seconds, compare the test pad to the color
chart at the end of this lab. If the color falls between two colors
in the color chart, estimate your result.
Record your results in Table 6 on the Week 2 Lab Reporting
Form.
23. Repeat the procedure for both Dasani® and Fiji® Bottled
Water. Record your results for both in Table 6
on the Week 2 Lab Reporting Form and then answer all of the
post lab questions on the Week 2 Lab Re-
porting Form.
33
Water Quality and Contamination
Test Strip Key:
Ammonia (mg/L):
Chloride (mg/L):
4 in 1 Test Strip:
0 10 30 60 100 200 400
0
500
1000
1500
2000
≥3000
*Note there are four pads on this test strip. From top to bottom
(with the bottom of the strip being the handle),
the pads test for pH, Chlorine, Alkalinity, and Hardness.
Example:
pH:
pH Chlor. Alk. Hard
(test strip handle)
Total Chlorine (mg/L):
Total Alkalinity (mg/L):
Total Hardness (mg/L):
0 0.2 1.0 4.0 10.0
0 40 80 120 180 240 500
0 50 120 250 425 1000
Soft Hard Very Hard
34
Water Quality and Contamination
Test Strip Key (cont.):
Phosphate (ppm):
0 10 25 50 100
Total Iron (ppm): 0 0.15 0.3 0.6 1 2 5
1. Form based on your observations.
35
Weather and Climate Change
Appendix
Good Lab Techniques
36
Good Lab Techniques
Good Laboratory Techniques
Science labs, whether at universities or in your home, are places
of adventure and discovery. One of the first
things scientists learn is how exciting experiments can be.
However, they must also realize science can be
dangerous without some instruction on good laboratory
practices.
• Read the protocol thoroughly before starting any new
experiment.
You should be familiar with the action required every step of
the
way.
• Keep all work spaces free from clutter and dirty dishes.
• Read the labels on all chemicals, and note the chemical safety
rating
on each container. Read all Material Safety Data Sheets
(provided
on www.eScienceLabs.com).
• Thoroughly rinse lab ware (test tubes, beakers, etc.) between
experi-
ments. To do so, wash with a soap and hot water solution using
a
bottle brush to scrub. Rinse completely at least four times. Let
air
dry
• Use a new pipet for each chemical dispensed.
• Wipe up any chemical spills immediately. Check MSDSs for
special
handling instructions (provided on www.eScienceLabs.com).
• Use test tube caps or stoppers to cover test tubes when shaking
or
mixing – not your finger!
A B C
Figure 1: A underpad will
prevent any spilled liquids
from contaminating the sur-
face you work on.
Figure 2: Special measuring tools in make experimentation
easier and more accu- rate in
the lab. A shows a beaker, B graduated cylinders, and C test
tubes in a test tube rack.
67
Good Lab Techniques
• When preparing a solution, refer to a protocol for any specific
instructions on preparation. Weigh out the desired amount of
chemicals, and transfer to a beaker or graduated cylinder.
Add LESS than the required amount of water. Swirl or stir to
dissolve the chemical (you can also pour the solution back
and forth between two test tubes), and once dissolved, trans-
fer to a graduated cylinder and add the required amount of
liquid to achieve the final volume.
• A molar solution is one in which one liter (1L) of solution
con-
tains the number of grams equal to its molecular weight.
For example:
1M = 110 g CaCl x 110 g CaCl/mol CaCl
(The formula weight of CaCl is 110 g/mol)
Figure 3: Disposable pipettes aid in ac-
curate measuring of small volumes of
liquids. It is important to use a new pi-
pette for each chemical to avoid con-
tamination.
• A percent solution can be prepared by percentage of weight of
chemical to 100ml of solvent (w/v) , or
volume of chemical in 100ml of solvent (v/v).
For example:
20 g NaCl + 80 mL H2O = 20% w/v NaCl solution
• Concentrated solutions, such as 10X, or ten times the normal
strength, are diluted such that the final
concentration of the solution is 1X.
For example:
To make a 100 mL solution of 1X TBE from a 10X solution:
10 mL 10X TBE + 90 mL water = 100ml 1X TBE
• Always read the MSDS before disposing of a chemical to
insure it does not require extra measures.
(provided on www.eScienceLabs.com)
• Avoid prolonged exposure of chemicals to direct sunlight and
extreme temperatures. Immediately se-
cure the lid of a chemical after use.
• Prepare a dilution using the following equation:
c1v1 = c2v2
Where c1 is the concentration of the original solution, v1 is the
volume of the original solution, and
c2 and v2 are the corresponding concentration and volume of
the final solution. Since you know c1,
68
Good Lab Techniques
c2, and v2, you solve for v1 to figure out how much of the
original solution is needed to make a cer-
tain volume of a diluted concentration.
• If you are ever required to smell a chemical, always waft a gas
toward you, as shown in the figure
below.. This means to wave your hand over the chemical
towards you. Never directly smell a
chemical. Never smell a gas that is toxic or otherwise
dangerous.
• Use only the chemicals needed for the activity.
• Keep lids closed when a chemical is not being used.
• When diluting an acid, always slowly pour the acid into the
water. Never pour water into an acid,
as this could cause both splashing and/or an explosion.
• Never return excess chemical back to the original bottle. This
can contaminate the chemical sup-
ply.
• Be careful not to interchange lids between different chemical
bottles.
• When pouring a chemical, always hold the lid of the chemical
bottle between your fingers. Never
lay the lid down on a surface. This can contaminate the
chemical supply.
• When using knives or blades, always cut away from yourself.
69
© 2012 eScience Labs, LLC - All rights reserved
68
Lab 2Concepts to ExploreIntroductionExperiment 1: Effects
of Groundwater ContaminationProcedureExperiment 2: Water
TreatmentMaterialsProcedureExperiment 3: Drinking Water
QualityMaterialsProcedureAmmonia Test StripChloride Test
Strip4 in 1 Test StripPhosphate Test StripIron Test
StripAmmonia (mg/L):pH:Total Chlorine (mg/L):Test Strip Key
(cont.):Phosphate (ppm):AppendixA B C© 2012 eScience Labs,
LLC - All rights reserved

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  • 1. Environmental Science Table of Contents 37 Lab 3 Biodiversity Biodiversity Concepts to Explore • Biodiversity • Species diversity
  • 2. • Ecosystem diversity • Genetic diversity • Natural selection • Extinction Introduction Biodiversity, short for biological diversity, includes the genetic variation between all organisms, species, and populations, and all of their complex communities and ecosystems. It also reflects to the interrelatedness of genes, species, and ecosystems and their interactions with the environment. Biodiversity is not evenly distrib- uted across the globe; rather, it varies greatly and even varies within regions. It is partially ruled by climate, whereas tropical regions can support more species than a polar climate. In whole, biodiversity represents variation within three levels: • Species diversity • Ecosystem diversity
  • 3. • Genetic diversity It should be noted that diversity at one of these levels may not correspond with diversity within other levels. The degree of biodiversity, and thus the health of an ecosystem, is im- pacted when any part of that ecosystem becomes endan- gered or extinct. The term species refers to a group of similar organisms that reproduce among themselves. Species diversity refers to the variation within and between populations of species, as well as between different species. Sexual reproduction criti- cally contributes to the variation within species. For exam- ple, a pea plant that is cross-fertilized with another pea plant can produce offspring with four different looks! This genetic mixing creates the diversity seen today. Figure 1: There are more than 32,000 species of fish – more than any other vertebrate! 39
  • 4. Biodiversity Ecosystem diversity examines the different habitats, biological communities, and ecological processes in the biosphere, as well as variation within an individual ecosystem. The differences in rainforests and deserts represent the variation between ecosystems. The physical characteristics that determine ecosystem diversity are complex, and include biotic and abiotic factors. ? Did You Know... A present day example of natural selection can be seen in the cray- fish population. The British crayfish are crustaceans that live in rivers in England. The American crayfish was introduced to the same bodies
  • 5. of water that were already populat- ed by the British crayfish. The American crayfish are larger, more aggressive and carry an infection that kills British crayfish but to which they are immune. As a re- sult, the British crayfish are de- creasing in number and are ex- pected to become extinct in Britain within the next 50 years. Thus, the American crayfish have a genetic variation that gives them an ad- vantage over the British crayfish to survive and reproduce. The variation of genes within individual organisms is genetic diversity. This can be measured within a species as well as between species. It plays an important role in survival and adaptability of organisms to changing environments. Diversity is also influenced by natural selection, the key mechanism of evolution. The process of natural selection describes competition be- tween individual species for resources such as food and space (habitat). Genetic variations among species provide an advantage over other species if those variations result in an ability to survive and repro- duce more effectively.
  • 6. Evidence that supports the theory of natural selection include the fossil record of change in earlier species, the chemical and anatomical simi- larities of related life forms, the geographical distribution of related spe- cies, and the recorded genetic changes in living organisms over many generations. Take for example, homologous structures among different species, such as the wing of a bird and the forearm of a human. These structures provide evidence that embryologically similar structures can give rise to different functions based on the needs of the organism. Note that natural selection does not try to explain the origin of life but rather the later evolution of organisms over time. Biodiversity is important to the process of evolution because it provides the framework on top of which natural selection can occur. As dis- cussed above, natural selection determines the genetic fitness, an or- ganism's genetic contribution to the next generation, of an organism. Natural selection occurs by selecting one trait as "more advantageous" in a certain environment than anoth- er. The root of this selection is biodiversity. Species extinction is not new; species have been evolving and
  • 7. dying out since life began. Now, however, species extinction is occurring at an alarming rate, almost entirely as a direct result of human activities. Sci- 40 Biodiversity entists recognize five major mass extinctions in the Earth’s history. The extinctions are measured in terms of large groups of related species, called families. The five mass extinction episodes occurred because of major changes in the prevailing ecological conditions brought about by climate change, cataclysmic volcanic erup- tions, or collisions with giant meteors. The sixth mass extinction appears to be in progress now, and the pri- mary cause is environmental change brought about by human activities. Some examples of species on the “endangered” list are the ivory billed woodpecker, amur leopard, javan rhinoceros, northern great whale, mountain gorilla, and the leatherback sea turtle. Figure 2: The amur leopard is at risk of extinction. Loss of an individual species can have various effects on the remaining species in an ecosystem. These ef- fects depend upon the how important the species is in the ecosystem. Individual species and ecosystems
  • 8. have evolved over millions of years into a complex interdependence. If you remove enough of the key spe- cies on which the framework is based, then the whole ecosystem may be in danger of collapsing. Regardless of a species’ place in the ecosystem, it is important for humans to take care of the world around us. As peo- ple become more aware of how their actions impact all living things they can make adjustments in an effort to preserve life on all levels. 41 Biodiversity There are many activities that humans take part in that impact the environment and biodiversity. The exhaust from automobile and aircraft travel as well as smoke stacks from industrial plants are the leading causes of air pollution, which can have harmful effects on natural resources and organisms. Two other important factors which can have an effect on biodiversity are overpopulation and affluence. Overpopulation means that there are more people than resources to meet their needs. As people become more affluent there is an increase in per capita resource utilization. All of these factors contribute to overharvesting, habitat degradation, and in- creased pollution which threaten biodiversity. 42
  • 9. Biodiversity Demonstration 1: Interdependence of Species In this lab, you will use the information provided above to demonstrate how the presence or absence of one species can affect the others in an ecosystem. Follow the procedure below to complete Demonstration 1 on the interdependence of species. Materials 5 different colored beads: White bead represents lichen Orange bead represents trees Red bead represents flowers Yellow bead represents bees Blue bead represents humans Lichens Lichens play a part in the creation of soils from which plants
  • 10. can obtain nutrients. Like all living organisms, lichens need nutrients and energy to grow. Nutrients may be obtained from the air (including dust), water, and from the substrate organisms grows on. They obtain energy through photosynthesis, which is the role of the algal partner. They may also be incidentally fertilized by bird and insect dung. Trees Most trees, flowers and plants depend on soil for food (nutrients). Fruiting trees depend on bees as one means of pollination. Flowers Forest flowers and plants depend on trees for shade and wind protection as well as soils for nutri- ents. Bees Bees depend on flowering plants and trees for food. Humans Humans depend upon bees for honey and more importantly for fruit from trees they pollinate.
  • 11. 43 Biodiversity Procedure 1. Download the Week 3 Lab Reporting Form from the course instructions. As you conduct the demonstra- tion and the experiment, record any hypotheses, observations, and data on that form. 2. Place all of the beads in a bag. 3. Randomly choose 4 beads from the bag. 4. Identify each bead by the color code in the materials box. 5. Record which species is missing in Table 1 on the Week 3 Lab Reporting Form. 6. Repeat this process 3 more times (or until 3 different beads are taken out of the diagram). Be sure to rec- ord which species is missing from each round in Table 1 and answer the Post-Lab questions on the Week
  • 12. 3 Lab Reporting Form. Experiment 1: Diversity of Plants Variations in growing conditions, climate, and numerous other factors can alter the biodiversity of an ecosys- tem. As such, biodiversity is often utilized as an indicator of ecosystem health. In this experiment, you will grow a sample of seeds under two different conditions. Follow the procedure below to complete Experiment 1 on the diversity of plants. Materials Seed mixture (zinnia, marigold, morning glory, cosmos, and ryegrass) Potting soil (2) 5.5 x 3.5 in Peat pots 10 mL Graduated cylinder *Water
  • 13. *You must provide Procedure 1. Read through the Experiment 1 procedure and then record your hypothesis on the biodiversity of seeds grown under two separate conditions on the Week 3 Lab Reporting Form. 2. Fill your pots loosely with soil until the soil is approximately 1 inch from the top. 3. Pour approximately 40 mL of tap water into your pots (less if the soil becomes very wet). 44 Biodiversity
  • 14. 4. Lightly scatter your seeds on top of the soil in each container. This should be a random assignment of seeds to each pot. 5. Press each seed down about ½ inch into the soil. 6. Place one pot in a sunny, indoor location (on a window sill that receives sunlight) and the second pot in a shaded, indoor location (away from all windows, this pot should not be placed in the dark, just away from direct sunlight). 7. Observe and water your seeds every day until you see them grow. These seeds will germinate quickly (3 - 7 days). 8. Complete Table 2 on the Week 3 Lab Reporting Form after approximately 1 - 2 weeks (or when you see a reasonable amount of plant growth in the peat pot) and answer all Post-Lab Questions on the Week 3 Lab Reporting Form. Table 3 (provided on the following page) provides pictures of the germinated seeds to help you determine when you should begin entering data, and what each plant looks like.
  • 15. 45 Weather and Climate Change Table 3: Picture and Description of Seedlings Grown from Seed Mixture Species Observed Picture Description Zinnia Short stems with dark green, rounded leaves Marigold Stems are shorter than cosmos with long skinny leaves (but wid- er than the cosmos leaves) with rounded tips Morning Glory Tall stems with elephant ear shaped leaves Cosmos
  • 16. Tall stems with long, pointed leaflets; a lighter green leaf com- pared to the marigold Ryegrass Long, skinny strands of green grass 46 Appendix Good Lab Techniques Good Lab Techniques Good Laboratory Techniques Science labs, whether at universities or in your home, are places
  • 17. of adventure and discovery. One of the first things scientists learn is how exciting experiments can be. However, they must also realize science can be dangerous without some instruction on good laboratory practices. • Read the protocol thoroughly before starting any new experiment. You should be familiar with the action required every step of the way. • Keep all work spaces free from clutter and dirty dishes. • Read the labels on all chemicals, and note the chemical safety rating on each container. Read all Material Safety Data Sheets (provided on www.eScienceLabs.com). • Thoroughly rinse lab ware (test tubes, beakers, etc.) between experi- ments. To do so, wash with a soap and hot water solution using a bottle brush to scrub. Rinse completely at least four times. Let air dry • Use a new pipet for each chemical dispensed.
  • 18. • Wipe up any chemical spills immediately. Check MSDSs for special handling instructions (provided on www.eScienceLabs.com). • Use test tube caps or stoppers to cover test tubes when shaking or mixing – not your finger! A B C Figure 1: A underpad will prevent any spilled liquids from contaminating the sur- face you work on. Figure 2: Special measuring tools in make experimentation easier and more accu- rate in the lab. A shows a beaker, B graduated cylinders, and C test tubes in a test tube rack. 67 Good Lab Techniques
  • 19. • When preparing a solution, refer to a protocol for any specific instructions on preparation. Weigh out the desired amount of chemicals, and transfer to a beaker or graduated cylinder. Add LESS than the required amount of water. Swirl or stir to dissolve the chemical (you can also pour the solution back and forth between two test tubes), and once dissolved, trans- fer to a graduated cylinder and add the required amount of liquid to achieve the final volume. • A molar solution is one in which one liter (1L) of solution con- tains the number of grams equal to its molecular weight. For example: 1M = 110 g CaCl x 110 g CaCl/mol CaCl (The formula weight of CaCl is 110 g/mol) Figure 3: Disposable pipettes aid in ac- curate measuring of small volumes of liquids. It is important to use a new pi- pette for each chemical to avoid con- tamination. • A percent solution can be prepared by percentage of weight of chemical to 100ml of solvent (w/v) , or volume of chemical in 100ml of solvent (v/v). For example:
  • 20. 20 g NaCl + 80 mL H2O = 20% w/v NaCl solution • Concentrated solutions, such as 10X, or ten times the normal strength, are diluted such that the final concentration of the solution is 1X. For example: To make a 100 mL solution of 1X TBE from a 10X solution: 10 mL 10X TBE + 90 mL water = 100ml 1X TBE • Always read the MSDS before disposing of a chemical to insure it does not require extra measures. (provided on www.eScienceLabs.com) • Avoid prolonged exposure of chemicals to direct sunlight and extreme temperatures. Immediately se- cure the lid of a chemical after use. • Prepare a dilution using the following equation: c1v1 = c2v2 Where c1 is the concentration of the original solution, v1 is the volume of the original solution, and c2 and v2 are the corresponding concentration and volume of
  • 21. the final solution. Since you know c1, 68 Good Lab Techniques c2, and v2, you solve for v1 to figure out how much of the original solution is needed to make a cer- tain volume of a diluted concentration. • If you are ever required to smell a chemical, always waft a gas toward you, as shown in the figure below.. This means to wave your hand over the chemical towards you. Never directly smell a chemical. Never smell a gas that is toxic or otherwise dangerous. • Use only the chemicals needed for the activity. • Keep lids closed when a chemical is not being used. • When diluting an acid, always slowly pour the acid into the water. Never pour water into an acid, as this could cause both splashing and/or an explosion.
  • 22. • Never return excess chemical back to the original bottle. This can contaminate the chemical sup- ply. • Be careful not to interchange lids between different chemical bottles. • When pouring a chemical, always hold the lid of the chemical bottle between your fingers. Never lay the lid down on a surface. This can contaminate the chemical supply. • When using knives or blades, always cut away from yourself. 69 © 2012 eScience Labs, LLC - All rights reserved 68 Lab 3Concepts to ExploreIntroductionDemonstration 1: Interdependence of SpeciesLichensMaterialsProcedureAppendixA B C© 2012 eScience Labs, LLC - All rights reserved
  • 23. Lab 2 – Water Quality and Contamination Experiment 1: Effects of Groundwater Contamination Table 1: Water Observations (Smell, Color, Etc.) Beaker Observations 1 2 3 4 5 6 7 8 POST LAB QUESTIONS 1. Develop hypotheses on the ability of oil, vinegar, and laundry detergent to contaminate groundwater. a. Oil hypothesis = b. Vinegar hypothesis = c. Laundry detergent hypothesis = 2. Based on the results of your experiment, would you reject or accept each hypothesis that you produced in question 1?
  • 24. Explain how you determined this. a. Oil hypothesis accept/reject = b. Vinegar hypothesis accept/reject = c. Laundry detergent hypothesis accept/reject = 3. What affects did each of the contaminants have on the water in the experiment? Which contaminant seemed to have the most potent effect on the water? Answer = 4. Using at least 1 scholarly source, discuss what type of affects these contaminants (oil, vinegar, detergent) might have on a town’s water source and the people who drank the water? Answer = 5. Describe what type of human activity would cause contaminants like oil, acid and detergents to flow into the water supply? Additionally, what other items within your house do you believe could contaminate the water supply if you were to dump them onto the ground? Answer = Experiment 2: Water Treatment POST LAB QUESTIONS 1. Develop a hypothesis on the ability of your filtration technique to remove contaminants. Hypothesis = 2. Based on the results of your experiment, would you reject or accept the hypothesis that you produced in question 1? Explain how you determined this. Accept/Reject = 3. What are the differences in color, smell, visibility, etc. between the “contaminated” water and the “treated” water? Answer = 4. From the introduction to this lab, you know that there are typically five steps involved in the water treatment process.
  • 25. Identify the processes (e.g., coagulation) that were used in this lab and describe how they were performed. Answer = Experiment 3: Drinking Water Quality Table 2: Ammonia Test Results Water Sample Test Results Tap Water Dasani® Bottled Water Fiji® Bottled Water Table 3: Chloride Test Results Water Sample Test Results Tap Water Dasani® Bottled Water Fiji® Bottled Water Table 4: 4 in 1 Test Results Water Sample pH Total Alkalinity Total Chlorine Total Hardness Tap Water Dasani® Bottled Water
  • 26. Fiji® Bottled Water Table 5: Phosphate Test Results Water Sample Test Results Tap Water Dasani® Bottled Water Fiji® Bottled Water Table 6: Iron Test Results Water Sample Test Results Tap Water Dasani® Bottled Water Fiji® Bottled Water POST LAB QUESTIONS 1. Develop a hypothesis on which water source you believe will contain the most and least contaminants. Hypothesis = 2. Based on the results of your experiment, would you reject or accept the hypothesis that you produced in question 1? Explain how you determined this. Accept/reject = 3. Based on the results of your experiment, what major
  • 27. differences, if any, do you notice between the Dasani, Fiji, and tap water? Answer = 4. Based on your results, do you believe that bottled water is worth the price? Why or why not? Answer = *NOTE – Do not forget to go to Lab 3: Biodiversity, and complete “Experiment 1: Diversity of Plants” steps 1 through 6. Steps 1 through 6 need to be completed in order to be prepared for Week Three, however, results for this experiment will not be calculated until next week. Thus, while nothing is to be handed in for this experiment until the end of Week Three you must plant the seeds this week to ensure that you can complete week 3 on time. References Any sources utilized should be listed here. © eScience Labs, 2013 Environmental Science Table of Contents 21 Lab 2 Water Quality and Contamination
  • 28. Water Quality and Contamination Concepts to Explore • Usable water • Ground water • Surface water • Ground water contaminates • Water treatment • Drinking water quality Figure 1: At any given moment, 97% of the planet’s water is in the oceans. Only a small fraction of the remaining freshwater is usable by humans, underscoring the importance of treating our
  • 29. water supplies with care. Introduction It is no secret that water is one of the most valuable resources on planet Earth. Every plant and animal re- quires water to survive, not only for drinking, but also for food production, shelter creation and many other ne- cessities. Water has also played a major role in transforming the earth’s surface into the varied topography we see today. While more than 70% of our planet is covered in water, only a small percent of this water is usable freshwater. The other 99% of the water is composed primarily of salt water, with a small percentage being composed of 23 Water Quality and Contamination glaciers. Due to the high costs involved in transforming salt water into freshwater, the Earth’s population sur- vives off the less than 1% of freshwater available. Humans obtain freshwater from either surface water or groundwater. Surface water is the water that collects on the ground as a result
  • 30. of precipitation. The water that does not evaporate back into the atmosphere or infiltrate into the ground is typically collected in rivers, lakes, reser- voirs, and other bodies of water and is easily accessible. Precipitation Precipitation Precipitation Cloud formation Transpiration Evaporation Evaporation Groundwater
  • 31. Figure 2: Water is a renewable source, purified and delivered across the planet by the hydrological cycle. Groundwater, on the other hand, is precisely as the name suggests; water located underneath the ground. This water is stored in pores, fractures and other spaces within the soil and rock underneath the ground’s sur- face. Precipitation, along with snowmelt, infiltrates through the ground and accumulates in available under- ground spaces. Aquifers are areas in which water collects in sand, gravel, or permeable rock from which it can be extracted for usable freshwater. The depth of aquifers vary from less than 50 feet to well over 1,500 feet below the sur- face of the ground. The water within an aquifer typically does not flow through as it would through a river or stream, but instead soaks into the underground material, similar to a sponge. As aquifers are depleted by hu- man use, they are also recharged from precipitation seeping into the ground and restoring the water level. However, many times the recharge of the aquifers does not equal the amount of water that has been extract- ed. If that cycle continues, the aquifer will eventually dry up and will no longer be a viable source of groundwa- ter. 24 Water Quality and Contamination
  • 32. Water is the only substance that is found naturally in three forms: solid, liquid, and gas If the entire world’s supply of water could fit into a one- gallon jug, the fresh water available to use would equal less than one tablespoon Approximately 66% of the human body consists of wa- ter - it exists within every organ and is essential for its function While the water that precipitates down in the form of rain is relatively pure, it does not take long for water to pick up contaminants. There are natural, animal, and human- made sources of water pollutants. They can travel freely from one location to another via streams, rivers, and even groundwater. Pollutants can also trav-
  • 33. el from land or air into the water. Groundwater contamination most often occurs when human-made products such as motor oil, gasoline, acidic chemicals and other substances leak into aquifers and other groundwater storage areas. The most common source of contaminants come from leaking storage tanks, poorly main- tained landfills, and septic tanks, hazardous waste sites and the common use of chemicals such as pesti- cides and road salts. The dangers of consuming contaminated water are high. Many deadly diseases, poisons and toxins can reside in the contaminated water supplies and severely affect the health of those who drink the water. It is also believed that an increased risk of cancer may result from ingesting contaminated groundwater. With the many contaminants that can infiltrate our wa- ter supply, it is crucial that there be a thorough water treatment plan in place to purify the water and make it drinkable. While each municipality has its own water treatment facility, the process is much the same at each location. Figure 3: Sedimentation tanks, such as those shown above, are used to settle the sludge and remove oils and fats in sewage. This step can remove a good por- tion of the biological oxygen demand from the sew- age, a key step before progressing with the treat-
  • 34. ments and eventually releasing into the ground or body of water. 25 Water Quality and Contamination The process begins with aeration in which air is added to the water to let trapped gases escape while increasing the amount of oxygen within the water. The next step is called coagulation or flocculation, in which chemicals, such as filter alum, are added to the incoming water and then stirred vigor- ously in a powerful mixer. The alum causes compounds such as carbonates and hydroxides to form tiny, sticky clumps called floc that attract dirt and other small particles. When the sticky clumps combine with the dirt they become heavy and sink to the bottom. In the next step, known as sedimentation, the heavy particles that sank to the bottom during coagula- tion are separated out and the remaining water is sent on to filtration. During filtration, the water passes through filters made of layers of sand, charcoal, gravel and pebbles that help filter out the smaller particles that have passed through until this point. The last step is called disinfection in which chlorine and/or other disinfectants are added to kill any bac- Figure 4: Fresh water is essen- tial to humans and other land- based life. Contaminated water must be treated before it can be released into the water supply.
  • 35. teria that may still be in the water. At this point the water is stored until it is distributed through various pipes to city residents and businesses. After the water goes through the treatment process, it must also pass the guidelines stated in the Safe Drinking Water Act in which various components are tested to ensure that the quality of the water is sufficient for drinking. There are currently over 65 contaminants that must be monitored and maintained on a regular basis to keep local drinking water safe for the public. Some of these chemical regulations include lead, chromium, selenium and arsenic. Other com- ponents such as smell, color, pH and metals are also monitored to ensure residents are provid- ed clean and safe drinking water. 26 Water Quality and Contamination Experiment 1: Effects of Groundwater Contamination In this lab you will test the effects of common pollutants on groundwater. When mixed with water, everyday items such as laundry detergent, oil, and vinegar can alter the color, smell, and taste of water. You have likely observed these changes through everyday activities such as adding laundry detergent to water in the washing
  • 36. machine, or noticing oil within a puddle on the street. Many of these chemicals end up dispersing throughout our environment, and while soil bacteria can reduce many of these contaminants, they may not be able to stop them from reaching our groundwater sources located beneath the soil. In Experiment 1 you will test the ability of soil to remove oil, vinegar, and laundry detergent from the environment before it reaches groundwa- ter. Follow the procedure below to complete Experiment 1 on the effects of groundwater contamination. Materials (8) 250 mL Beakers Permanent marker 3 Wooden stir sticks 100 mL Graduated cylinder 10 mL Vegetable oil 10 mL Vinegar 10 mL Liquid laundry detergent 100 mL Beaker 240 mL Soil Funnel
  • 37. Cheesecloth *Scissors *Water *You must provide Procedure 1. Download the Week 2 Lab Reporting Form from the course instructions. As you conduct all 3 experi- ments, record hypotheses, observations, and data on that form. 2. Read through the Experiment 1 procedure and then record your hypotheses on the ability of oil, vinegar, and laundry detergent to contaminate groundwater on the Week 2 Lab Reporting Form. You should pro- vide one hypothesis for each situation. 3. Use the permanent marker to label the beakers 1 - 8. 4. Set Beakers 5 - 8 aside. Fill Beakers 1 - 4 with 100 mL of
  • 38. water using your 100 mL graduated cylinder. 5. Record your observations of the water in Beaker 1 in Table 1 on the Week 2 Lab Reporting Form. Re- member to use a safe wafting technique to smell the solutions. 27 Water Quality and Contamination 6. Add 10 mL of vegetable oil to Beaker 2. Mix thoroughly with a wooden stir stick. Record your observations of the water in Beaker 2 in Table 1 on your Week 2 Lab Reporting Form. (Don’t forget to wash the gradu- ated cylinder between use!) 7. Add 10 mL vinegar to beaker 3. Mix thoroughly with a wooden stir stick. Record your observations of the water in Beaker 3 in Table 1 on your Week 2 Lab Reporting Form. 8. Add 10 mL of liquid laundry detergent to beaker 4. Mix thoroughly with a wooden stir stick. Record your observations of the water in Beaker 4 in Table 1 on your Week
  • 39. 2 Lab Reporting Form. 9. Cut your piece of cheesecloth into five different pieces (reserve one piece for the next experiment). Fold one piece of the cheesecloth so that you have a piece 4 layers thick and big enough to line the funnel. Place it inside the funnel. 10. Measure out 60 mL of soil using the 100 mL beaker and place it into the cheesecloth-lined funnel. 11. Place the funnel inside Beaker 5. 12. Pour the contents of Beaker 1 (water) through the funnel so that it filters into Beaker 5 for one minute. Record your observations of the filtered water in the beaker in Table 1 on your Week 2 Lab Reporting Form. 13. Discard the cheesecloth and soil from the funnel. 14. Repeat Steps 9 - 13 for Beakers 2, 3, and 4 and complete the Post-Lab questions on the Week 2 Lab Re- porting Form. (Filter the contents of Beaker 2 into Beaker 6, the
  • 40. contents of Beaker 3 into Beaker 7, and the contents of Beaker 4 into Beaker 8). 28 Water Quality and Contamination Experiment 2: Water Treatment With the many pollutants that are added to our water supply from daily human activity, it is important that we have a way to filter our water to make it safe for drinking. Wastewater treatment plants use sophisticated techniques to make water potable. In Experiment 2, you will use a similar technique to test the effectiveness of one filtering method on the ability to purify contaminated water. Follow the procedure below to complete Experiment 2 on the effects of one method of water treatment. Materials 100 mL Potting soil (2) 250 mL Beakers (2) 100 mL Beakers
  • 41. 100 mL Graduated cylinder 40 mL Sand 20 mL Activated charcoal 60 mL Gravel 1 Wooden stir stick Alum Funnel Cheesecloth Bleach Stopwatch *Water *You must provide Procedure
  • 42. 1. Read through the Experiment 2 procedure and then record your hypothesis on the ability of your filtration technique to remove contaminants on your Week 2 Lab Reporting Form. 2. Add 100 mL of soil to the 250 mL beaker. Fill to the 200 mL mark with water. 3. Pour the soil solution back and forth between the two 250 mL beakers for a total of 15 times. 4. After the solution is created, pour 10 mL of the now “contaminated” water into a clean 100 mL beaker. This sample will be used to compare to the “treated” water at the end of the filtration process. 5. Add 10 grams of alum (all of the contents in the bag you have been given) to the 250 mL beaker contain- ing the “contaminated” water. Slowly stir the mixture with a wooden stir stick for 1-2 minutes. Let the so- lution sit for 15 minutes. 6. In the meantime, rinse out the empty 250 mL beaker. Place the funnel into the clean 250 mL beaker. Fold a piece of cheesecloth so that you have a piece 4 layers thick
  • 43. that is big enough to line the funnel. Place 29 Water Quality and Contamination it inside the funnel. 7. Begin layering the funnel, starting by pouring 40 mL of sand into the cheesecloth-lined funnel, then 20 mL activated charcoal, then 40 mL gravel. Use a 100 mL beaker to measure these amounts. 8. To solidify the filter, slowly pour clean tap water through the filter until the funnel is full. Discard the rinse water from the beaker and repeat four more times. Return the funnel to the top of the beaker and let sit for 5 minutes before emptying the beaker and continuing the experiment. 9. Now, without mixing up the current sediment in the “contaminated” water jar, pour about 3/4 of the “contaminated” water into the funnel. Let it filter through the funnel into the beaker for 5 minutes. 10. Note the smell of the filtered water, comparing it to the 10
  • 44. mL sample taken from the mixture in Step 3. 11. Remove the filter and add a few drops of bleach solution to the filtered water within the beaker. Stir the water and bleach combination slowly for about 1 minute. 12. The “contaminated” water has now been filtered. Compare the newly created “treated” water with the 10 mL sample of the initial “contaminated” water and answer the Post-Lab questions on the Week 2 Lab Re- porting Form. 30 Water Quality and Contamination Experiment 3: Drinking Water Quality Bottled water is a billion dollar industry within the United States alone. Still, various reports have shown that many bottled water products contain the same chemical contaminants as our tap water. In Experiment 3, you will test the quality of two separate bottled waters and your tap water by measuring a variety of chemical com- ponents within the water. Follow the procedure below to complete Experiment 3 on drinking water quality.
  • 45. Materials Dasani® bottled water Fiji® bottled water Ammonia test strips Chloride test strips 4 in 1 test strips Phosphate test strips Iron test strips (3) 250 mL Beakers Permanent marker Stopwatch Parafilm® Pipettes (3) Foil packets of reducing powder *Tap water
  • 46. *You must provide Procedure 1. Read through the Experiment 3 procedure and then record your hypothesis on which water source you believe will have the most and least contaminants on the Week 2 Lab Reporting Form. 2. Label three 250 mL beakers Tap Water, Dasani® and Fiji®. Pour 100 mL of the each type of water into the corresponding beakers. Ammonia Test Strip 3. Locate the ammonia test strips. Begin by placing the test strip into the tap water sample and vigorously moving the strip up and down in the water for 30 seconds, making sure that the pads on the test strip are always submerged.
  • 47. 4. Remove the test strip from the water and shake off the excess water. 5. Hold the test strip level, with the pad side up, for 30 seconds. 31 Water Quality and Contamination 6. Read the results by turning the test strip so the pads are facing away from you. Compare the color of the small pad to the color chart at the end of the lab. Record your results in Table 2 on the Week 2 Lab Re- porting Form. 7. Repeat the procedure for both Dasani® and Fiji|® bottled water. Record your results for both in Table 2 on the Week 2 Lab Reporting Form. Chloride Test Strip 8. Locate the chloride test strips. Begin by immersing all the
  • 48. reaction zones (the pads) of the test strip in to the tap water sample for 1 second. 9. Shake off the excess liquid from the test strip and after 1 minute, determine which color row the test strip most noticeably coincides with on the color chart at the end of the lab. Record your results in Table 3 on the Week 2 Lab Reporting Form. 10. Repeat the procedure for both Dasani® and Fiji® Bottled Water. Record your results for both in Table 3. 4 in 1 Test Strip 11. Locate the 4 in 1 test strips. Begin by dipping the test strip in the tap water for 5 seconds with a gentle back and forth motion. 12. Remove the test strip from the water and shake once, briskly, to remove the excess water. 13. Wait 20 seconds and then using the color chart at the end of this lab, match the test strip to the pH, Total
  • 49. Alkalinity, Total Chlorine, and Total Hardness on the color chart. Be sure to do all of the readings within seconds of each other. Record your results in Table 4 on the Week 2 Lab Reporting Form. 14. Repeat the procedure for both Dasani® and Fiji® Bottled Water. Record your results for both in Table 4. Phosphate Test Strip 15. Locate the phosphate test strips. Being by dipping the test strip into the tap water for 5 seconds. 16. Remove the test strip from the water and hold horizontal, with the pad side up, for 45 seconds. Do not shake the excess water from the test strip. 32 Water Quality and Contamination 17. Compare the results on the pad of the test strip with the
  • 50. color chart at the end of this lab. Record your results in Table 5 on the Week 2 Lab Reporting Form. 18. Repeat the procedure for both Dasani® and Fiji® bottled water. Record your results for both in Table 5. Iron Test Strip 19. Locate the iron test strips. Begin by removing 70 mL of water from each beaker and discarding it, leaving a total of 30 mL within each of the three beakers. 20. Beginning with the tap water, open one foil packet and add the powder contents to the beaker. Cover the beaker with a piece of Parafilm® and shake the beaker vigorously for 15 seconds. 21. Remove the Parafilm® and dip the test pad of the iron test strip into the tap water sample, rapidly moving it back and forth under the water for 5 seconds. 22. Remove the strip and shake the excess water off. After 10 seconds, compare the test pad to the color
  • 51. chart at the end of this lab. If the color falls between two colors in the color chart, estimate your result. Record your results in Table 6 on the Week 2 Lab Reporting Form. 23. Repeat the procedure for both Dasani® and Fiji® Bottled Water. Record your results for both in Table 6 on the Week 2 Lab Reporting Form and then answer all of the post lab questions on the Week 2 Lab Re- porting Form. 33 Water Quality and Contamination Test Strip Key: Ammonia (mg/L): Chloride (mg/L):
  • 52. 4 in 1 Test Strip: 0 10 30 60 100 200 400 0 500 1000 1500 2000 ≥3000
  • 53. *Note there are four pads on this test strip. From top to bottom (with the bottom of the strip being the handle), the pads test for pH, Chlorine, Alkalinity, and Hardness. Example: pH: pH Chlor. Alk. Hard (test strip handle) Total Chlorine (mg/L): Total Alkalinity (mg/L): Total Hardness (mg/L):
  • 54. 0 0.2 1.0 4.0 10.0 0 40 80 120 180 240 500 0 50 120 250 425 1000 Soft Hard Very Hard 34 Water Quality and Contamination Test Strip Key (cont.): Phosphate (ppm): 0 10 25 50 100
  • 55. Total Iron (ppm): 0 0.15 0.3 0.6 1 2 5 1. Form based on your observations. 35 Weather and Climate Change Appendix Good Lab Techniques 36 Good Lab Techniques Good Laboratory Techniques Science labs, whether at universities or in your home, are places of adventure and discovery. One of the first things scientists learn is how exciting experiments can be. However, they must also realize science can be
  • 56. dangerous without some instruction on good laboratory practices. • Read the protocol thoroughly before starting any new experiment. You should be familiar with the action required every step of the way. • Keep all work spaces free from clutter and dirty dishes. • Read the labels on all chemicals, and note the chemical safety rating on each container. Read all Material Safety Data Sheets (provided on www.eScienceLabs.com). • Thoroughly rinse lab ware (test tubes, beakers, etc.) between experi- ments. To do so, wash with a soap and hot water solution using a bottle brush to scrub. Rinse completely at least four times. Let air dry • Use a new pipet for each chemical dispensed. • Wipe up any chemical spills immediately. Check MSDSs for special handling instructions (provided on www.eScienceLabs.com).
  • 57. • Use test tube caps or stoppers to cover test tubes when shaking or mixing – not your finger! A B C Figure 1: A underpad will prevent any spilled liquids from contaminating the sur- face you work on. Figure 2: Special measuring tools in make experimentation easier and more accu- rate in the lab. A shows a beaker, B graduated cylinders, and C test tubes in a test tube rack. 67 Good Lab Techniques • When preparing a solution, refer to a protocol for any specific instructions on preparation. Weigh out the desired amount of
  • 58. chemicals, and transfer to a beaker or graduated cylinder. Add LESS than the required amount of water. Swirl or stir to dissolve the chemical (you can also pour the solution back and forth between two test tubes), and once dissolved, trans- fer to a graduated cylinder and add the required amount of liquid to achieve the final volume. • A molar solution is one in which one liter (1L) of solution con- tains the number of grams equal to its molecular weight. For example: 1M = 110 g CaCl x 110 g CaCl/mol CaCl (The formula weight of CaCl is 110 g/mol) Figure 3: Disposable pipettes aid in ac- curate measuring of small volumes of liquids. It is important to use a new pi- pette for each chemical to avoid con- tamination. • A percent solution can be prepared by percentage of weight of chemical to 100ml of solvent (w/v) , or volume of chemical in 100ml of solvent (v/v). For example: 20 g NaCl + 80 mL H2O = 20% w/v NaCl solution
  • 59. • Concentrated solutions, such as 10X, or ten times the normal strength, are diluted such that the final concentration of the solution is 1X. For example: To make a 100 mL solution of 1X TBE from a 10X solution: 10 mL 10X TBE + 90 mL water = 100ml 1X TBE • Always read the MSDS before disposing of a chemical to insure it does not require extra measures. (provided on www.eScienceLabs.com) • Avoid prolonged exposure of chemicals to direct sunlight and extreme temperatures. Immediately se- cure the lid of a chemical after use. • Prepare a dilution using the following equation: c1v1 = c2v2 Where c1 is the concentration of the original solution, v1 is the volume of the original solution, and c2 and v2 are the corresponding concentration and volume of the final solution. Since you know c1, 68
  • 60. Good Lab Techniques c2, and v2, you solve for v1 to figure out how much of the original solution is needed to make a cer- tain volume of a diluted concentration. • If you are ever required to smell a chemical, always waft a gas toward you, as shown in the figure below.. This means to wave your hand over the chemical towards you. Never directly smell a chemical. Never smell a gas that is toxic or otherwise dangerous. • Use only the chemicals needed for the activity. • Keep lids closed when a chemical is not being used. • When diluting an acid, always slowly pour the acid into the water. Never pour water into an acid, as this could cause both splashing and/or an explosion. • Never return excess chemical back to the original bottle. This
  • 61. can contaminate the chemical sup- ply. • Be careful not to interchange lids between different chemical bottles. • When pouring a chemical, always hold the lid of the chemical bottle between your fingers. Never lay the lid down on a surface. This can contaminate the chemical supply. • When using knives or blades, always cut away from yourself. 69 © 2012 eScience Labs, LLC - All rights reserved 68 Lab 2Concepts to ExploreIntroductionExperiment 1: Effects of Groundwater ContaminationProcedureExperiment 2: Water TreatmentMaterialsProcedureExperiment 3: Drinking Water QualityMaterialsProcedureAmmonia Test StripChloride Test Strip4 in 1 Test StripPhosphate Test StripIron Test StripAmmonia (mg/L):pH:Total Chlorine (mg/L):Test Strip Key
  • 62. (cont.):Phosphate (ppm):AppendixA B C© 2012 eScience Labs, LLC - All rights reserved