Conservation of mass - this unit has been about keeping track of amounts of substances before and after chemical reactions. The record-keeping allows us to determine empirical and molecular formulas of substances. In addition, we can compare theoretical yields of products to actual measured masses to calculate a percent yield of product in an experiment. This is important for industries which track costs of expensive reactants! They will want to maximize the yield of a product that they sell while minimizing the use of an expensive reactant.
HW: Review for the exam scheduled for Wednesday.
Review Packet Answers:
Unit 5 - Moles, Empirical Formulas, Molecular Formulas
2. a. 101.087g; b. 96.0862g; c. 331.728g; d. 31.998g; e. 164.09g; f. 331.2g
4. a. 0.215 moles; b. 0.00361 moles; c. 13g; d. 1.29g; e. 85g
5. a. 9.03 X 10^20 atoms Zn; b. 80.0g O2; c. 0.0271 mol Na; d. 0.306 mol Cl;
e. 3.28 x 10^-14g Au
6. N2O5
7. MgO
8. C6H6; N2O4
9. C6H12O6
10. 88.8%
11. 77.8% Fe; 22.2% O
Unit 8 -Molar Volume and Gas Stoichiometry
1. 12.4 L; O2 would exert the most pressure.
2. 24 L
3. 3.02 L
6. a. 2NO + O2 => 2NO2
