IA Design and interesting reseach questions
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This document describes several experiments investigating the kinetics and rates of various chemical reactions through measuring changes over time. It includes studying the effect of temperature on the rate of decomposition of hydrogen peroxide and determining the activation energy using the iodine clock reaction. Other proposed experiments examine the rates of dissolution of seashells in carbonated water, dissolving of candies in water at different temperatures, and decolorization of dyes with changes in reactants.
![Effectiveness of I-
(catalyst) vs catalase (enzyme) in decomposition of H2O2
Determination of activation energy of decomposition of H2O2 by performing it at 5
diff temperature, and measuring the rate constant k. Use Arrhenius eqn to find Ea
Relationship between amount of catalyst used (MnO2) and activation energy (Ea) for
H2O2 decomposition. Will adding more catalyst (1, 2, 3, 4, 5)g lower/change the Ea
Determining the order of reaction for H2O2 + 2H+
+ 2I-
→ I2 + 2H2O.
Na2S2O3 is used to delay to reaction and 0.2% starch is used.
Rate Law = k [H2O2] [H+
] [I-
]
Comparative study bet catalyst and enzyme in the change in activation energy.
Activation energy determination using catalyst (I-
) and enzyme (catalase) for
decomposition H2O2 by performing it at different temperature, using arrhenius eqn
to determine Ea
Interesting research question on kinetics and rate studies.
Rate of decolourization of approved food dyes (Erythrosin B, Tartrazine, Indigo
carmine) with bleach. By changing the concentration of bleach, rate of decolorization
is measured spectroscopically using visible spec.
Rate of decolourization of chemical dyes, crystal violet with OH-
. By changing the
concentration of OH-
, rate of decolorization is measured spectroscopically using
visible spec.
Rate of evaporation of alcohol hand sanitizer/alcohol based perfume/moisturizers
(60, 70 80 85, 95% alcohol), by measuring the change in mass over a period of time.
(Determine zero, 1st
or 2nd
order reaction)
Rate of starch hydrolysis using amylase (enzyme) vs 4M HCI (catalyst) measured
spectrochemically. Starch + I2 is added, giving a blue black coloration. By adding
enzyme or catalyst, the blue coloration fades over time. Rate of decolorization can
be determined. Recommended using 5% starch and I2/I solution. (2g KI + 1gI2)
Using pressure sensor to determine 1st
order kinetic for CaCO3 decomposition in
eggshell in HCI.
CaCO3 + 2H+
→ Ca2+
+ CO2 + H2O. (Different type of eggs, salted egg, quail egg may
be used). HCI used is in excess, rate of decomposition is dependent only on CaCO3.
Rate Law = k [CaCO3]. Rate of pressure increase over time can be used.](https://image.slidesharecdn.com/iadesign-170503042431/85/IA-Design-and-interesting-reseach-questions-2-320.jpg)
IA Design and interesting reseach questions
- 1. IA on catalyst, enzyme, H2O2, and kinetics study H2O2 decomposes to H2O and O2. Very slow due to high Ea activation energy. Catalyst will lower Ea. Catalyst will not get consumed in a chemical rxn: Using KI as catalyst. Click here to view. Decomposition of H2O2 catalyzed by I- or transition metals or enzymes (catalase) H2O2 + I- → OI- + H2O H2O2 + OI- → H2O + O2 + I- Dependent variable:- O2/pressure build up over time or Conc of H2O2 left over time. Research Question: Effect of pH (pH 3, 5, 7, 8, 10) on the rate of decomposition of H2O2 Effect of temperature (20 - 50C) on the rate of decomposition of H2O2 Effect transition metal (Cu2+ , Mn2+ , Co2+ , Ni2+ ) on the rate of decomposition of H2O2 Effect of 3d transition metal with diff oxidation states on decomposition of H2O2
- 2. Effectiveness of I- (catalyst) vs catalase (enzyme) in decomposition of H2O2 Determination of activation energy of decomposition of H2O2 by performing it at 5 diff temperature, and measuring the rate constant k. Use Arrhenius eqn to find Ea Relationship between amount of catalyst used (MnO2) and activation energy (Ea) for H2O2 decomposition. Will adding more catalyst (1, 2, 3, 4, 5)g lower/change the Ea Determining the order of reaction for H2O2 + 2H+ + 2I- → I2 + 2H2O. Na2S2O3 is used to delay to reaction and 0.2% starch is used. Rate Law = k [H2O2] [H+ ] [I- ] Comparative study bet catalyst and enzyme in the change in activation energy. Activation energy determination using catalyst (I- ) and enzyme (catalase) for decomposition H2O2 by performing it at different temperature, using arrhenius eqn to determine Ea Interesting research question on kinetics and rate studies. Rate of decolourization of approved food dyes (Erythrosin B, Tartrazine, Indigo carmine) with bleach. By changing the concentration of bleach, rate of decolorization is measured spectroscopically using visible spec. Rate of decolourization of chemical dyes, crystal violet with OH- . By changing the concentration of OH- , rate of decolorization is measured spectroscopically using visible spec. Rate of evaporation of alcohol hand sanitizer/alcohol based perfume/moisturizers (60, 70 80 85, 95% alcohol), by measuring the change in mass over a period of time. (Determine zero, 1st or 2nd order reaction) Rate of starch hydrolysis using amylase (enzyme) vs 4M HCI (catalyst) measured spectrochemically. Starch + I2 is added, giving a blue black coloration. By adding enzyme or catalyst, the blue coloration fades over time. Rate of decolorization can be determined. Recommended using 5% starch and I2/I solution. (2g KI + 1gI2) Using pressure sensor to determine 1st order kinetic for CaCO3 decomposition in eggshell in HCI. CaCO3 + 2H+ → Ca2+ + CO2 + H2O. (Different type of eggs, salted egg, quail egg may be used). HCI used is in excess, rate of decomposition is dependent only on CaCO3. Rate Law = k [CaCO3]. Rate of pressure increase over time can be used.
- 3. Lightstick/cyalume experiment. Relationship between light intensity (light stick) with activation energy. Does light stick with higher intensity have higher Ea, or otherwise. Different light stick can be used, and light intensity is measured with light sensor at different temp. Arrhenius plot used to determine Ea. Light stick is immersed into beaker of water at different temp, and maximum light intensity was measured. Need to leave it for 5-10 mins for it to reach max intensity. Rate of dissolving/dissolution of solid candy/M&M in water at different temperature. Candies are placed in beaker of water at different temp, and rate of dissolving is measured by the decrease in mass of candy over time. Mass decrease over time (Rate of dissolving) can be determined using a electronic balance. If done at different temp, rate can be measured, and arrhenius plot can be used to determine Ea for candy. IA on environmental studies (Click here to view) Ocean acidification study. Artificial seawater was prepared in lab. CO2 was pump into seawater to simulate rxn: CO2 + H2O → H2CO3. Increase in carbonic acid cause pH to drop and causes coral/seashell to dissolve. 1st sample is carbonated. - CO2 was pump into seawater and measured using CO2 sensor. (ppm is recorded). 2nd sample is non carbonated.- Seawater continuously stirred (No CO2 was pump). 3rd sample is negative control. - Only seawater. Seashell/coral was added to 3 different samples shown above, and mass of coral was measured over time. pH sample was determined and Ca2+ concentration was measured using EDTA titration. Effect of carbonation of seawater on the mass of corals can be monitored by the decrease of mass over time. As seashell CaCO3 dissolves, Ca2+ ions will increase over time and pH will decrease over time.
- 4. Kinetics on Iodine Clock Reaction using H2O2 Click here to view Iodine clock reaction has many versions: Oxidizing agent - H2O2, KIO3, NaIO3, Na2S2O8 Reducing agent - KI, Na2S2O3, NaHSO3, Vitamin C Starch is need. Blue black colouration is seen. Activation energy determination for a chemical reaction. Determine activation energy of a reaction. Introduction. (Iodine clock reaction) Hydrogen peroxide (H2O2) react in acid, to produce iodine, I2 according to eqn: H2O2 + 2I- 2SO4 2- + I2 2S2O3 2- + I2→ S4O6 2- + 2I- Rate of rxn can be followed by measuring the time taken for the I2 forming to react with starch, appearance of blue black. Amt S2O3 2- added to indicate certain amt of I2 has to be formed before excess I2 reacts with starch. Experiment examines how rate varies with temperature for a fixed concentration of all solutions. Materials and chemicals Sodium thiosulfate Na2S2O3, 0.001 M Stop watch Kl, 0.5 M White paper Hydrogen peroxide H2O2 (3%) Water bath 0.2% starch
- 5. Procedure Effect of temperature 1. Measure 2 ml of 0.001 M sodium thiosulfate solution into a test tube A. 2. Add 1 ml 0.5M KI to same test tube A, and 2 drops starch. 3. Add 1 ml H2O2 to test tube B. 4. Incubate test tube A and B at room temperature for 10 mins. 5. After 10 mins, pour solution from test tube B to A. Record time blue colouration to form 6. Repeat step 1 – 5 at temperature of 4, 30, 50 and 70 °C. Adjust temp by a hot water bath. Test Tube A Test Tube B Temp/C Total vol 1 ml, 0.5M KI 2 ml, 0.001M S2O3 0.5ml 0.2% starch Conc 3% H2O2 1 ml each Time/s Rate = 1/Time 4 2.5 1 RT 2.5 1 30 2.5 1 50 2.5 1 70 2.5 1 Temp/K Total vol 1 ml, 0.5M KI 2 ml, 0.001M S2O3 0.5ml 0.2% starch Conc 3% H2O2 1 ml each Time/s Rate = 1/Time 277 2.5 1 RT 2.5 1 303 2.5 1 323 2.5 1 343 2.5 1 1. Rate of rxn is given by reciprocal of the time ( t 1 ).Using your results collected, - Plot a graph of Temp/C vs Rate ( t 1 ). - Plot a graph of Temp/K vs Rate ( t 1 ). 2. Plot another graph of ln k vertical vs Temp ( T 1 ) horizontal. Temp in Kelvin. 3. Calculate activation energy, Ea in kJmol-1 How does rate of reaction change with temperature? (What is your assumption?)