Dimensional analysis-measuring-data analysis.pdf
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The document covers dimensional analysis, measurement methods, and various measuring systems such as the English, metric, and International System of Units (SI). It details fundamental quantities and their respective base units, conversion factors, and provides examples and exercises related to calculating density, molar mass, and mole conversions. Additionally, it discusses scientific notation and temperature scales, along with instructions for a measurement activity.
Dimensional analysis-measuring-data analysis.pdf
- 1. Dimensional Analysis Measuring and Data Analysis
- 2. Dimensional Analysis ▪ Problem-solving method focused on units that describe matter and their relationships. ▪ Often uses conversion factors.
- 3. Conversion factors ▪ Ratio of equivalent values that express the same quantity in different units. ▪ Always equal to 1 ▪ Changes units without changing magnitude. https://assets.katomcdn.com/q_auto,f_auto/products/007/007-3216/007-3216.jpg
- 4. Measuring ▪ Comparing a quantity with its corresponding unit, so it is possible to determine how many times the unit is contained in this quantity. “medir."DiccionariodelaLenguaEspañola–22aed.2001.RealAcademiaEspañola.04Aug.2008<http://buscon.rae.es/draeI>
- 5. Measuring systems ▪ English system (British Imperial System) – around 1220 ▪ Metric system (decimal) – 1790 ▪ International System of Units (SI) - 1960 “Measurementsystem."EncyclopædiaBritannica.2008.EncyclopædiaBritannicaOnline.04Aug.2008<http://www.britannica.com/EBchecked/topic/1286365/measurement-system>.
- 6. Measuring systems ▪ Base units: based on objects or events from the physical world. ▪ Derived units: combinations of base units. Dingrando,Laurel,KathleenTallman,NicholasHainen,CherylWistrometal.Chemistry;MatterandChange. Columbus,Ohio:Glencoe/McGrawHill,2005
- 7. Fundamental quantities / base units ▪ Lenght: meter (m) ▪ Mass: kilogram (kg) ▪ Time: second (s) ▪ Thermodynamic temperature: kelvin (K) ▪ Amount of substance: mole (mol) ▪ Luminous intensity: candela (cd) ▪ Electric current: ampere (A)
- 8. Prefixes for SI units Dingrando,Laurel,KathleenTallman,NicholasHainen,CherylWistrometal.Chemistry;MatterandChange. Columbus,Ohio:Glencoe/McGrawHill,2005
- 12. Exercises
- 13. What volume is occupied by 16.4 g of mercury? The density of mercury is 13.6 g/mL.
- 14. A 3.2 cm-edge cube has a mass of 450 g. Calculate its density in lb/in3
- 15. A 50-mL graduated cylinder was filled with 15.9 mL of water. 30.0 g of an unknown metal (in the form of small pellets) was added to the graduated cylinder, causing the water level to rise to 17.3 mL. The possible identities of the metal are aluminum (d = 2.70 g/cm3), iron (d = 7.78 g/cm3), magnesium (d = 1.74 g/cm3), tin (d = 7.26 g/cm3), platinum (d = 21.5 g/cm3), beryllium (d = 1.85 g/cm3), or copper (d = 8.94 g/cm3). Identify the metal.
- 16. Calculate the molar mass for the following compounds : H2 SO4 As2 O3 C12 H22 O11 Ca3 (PO4 )2 HClO3 98 g/mol 198 g/mol 342 g/mol 310 g/mol 84.5 g/mol Calculating molar mass
- 18. … has a mass equal to the atomic (if elements) or molecular (if compounds) mass expressed in grams Molar mass (variable) … contains 6.022x1023 particles (atoms if element, molecules if compound or molecular element) Avogadro’s number (constant) … occupies a volume of 22.4 liters (only for gases at STP*) Molar volume (constant) One Mole… *STP = Standard Temperature (0°C = 273.15 K) and Pressure (1 atm = 760 mmHg = 101.3 kPa)
- 19. Mole conversions 1. How many molecules are in 3 moles of Al2 (SO4 )3 ? 2. How many moles are in 200 g of Fe2 O3 3. Determine the amount of molecules in 100 g of HgClO2
- 20. Mole conversions 1. How many molecules are in 3 liters at STP of H2 S(g) ? 2. How many molecules are in 340 g of H2 SO3 3. Determine the amount of moles in 1.45x1026 molecules of HCl
- 25. Temperature Scales 180° 100° 100° “Temperaturescales.”04Aug.2008http://abyss.uoregon.edu/~js/glossary/temperature_scale.html
- 26. Scientific Notation ▪ Numbers as multiple of two factors: 1 to 9 and 10n ▪ Larger than 1: n = (+) ▪ Smaller than 1: n = (-) ▪ Adding and substracting: SAME exponents! ▪ Multiplying: multiply factors, then add exponents. ▪ Dividing: divide factors, then substract exponents. Dingrando,Laurel,KathleenTallman,NicholasHainen,CherylWistrometal.Chemistry;MatterandChange. Columbus,Ohio:Glencoe/McGrawHill,2005
- 29. Exercises
- 31. References Dingrando, Laurel, Kathleen Tallman, Nicholas Hainen, Cheryl Wistrom et al. Chemistry; Matter and Change. Columbus, Ohio: Glencoe/McGraw Hill, 2005 “Measurement system." Encyclopædia Britannica. 2008. Encyclopædia Britannica Online. 04 Aug. 2008 <http://www.britannica.com/EBchecked/topic/1286365/ measurement-system>. “medir." Diccionario de la Lengua Española – 22a ed. 2001. Real Academia Española. 04 Aug. 2008 http://buscon.rae.es/draeI “Temperature scales.” 04 Aug. 2008 http://abyss.uoregon.edu/~js/glossary/temperature_sca le.html
- 32. Measuring… 1. Choose someone to work with today. 2. Take your notebook and pencil and/or mobile device with you. 3. Go out from the classroom and measure 10 different things using only the tools you have (notebook/pencil/mobile device). Write down the measurements. You will have 15 minutes to do this. 4. Come back to the classroom to share your results.