Unit 9 (Ch 10 & 12) SAO: Chemical Quantities & Stoichiometry
Vocabulary and Key Equations found at the end of each chapter
Ch 10 Objectives:
1. Describe the 3 methods of measuring the amount of something
2. Define Avogadro’s number as it relates to a mole of a substance
3. Distinguish among the atomic mass of a substance, its formula mass, and its molar mass based on quantity and
unit
4. Use the appropriate term for each of the three types of representative particles
5. Describe how the mass of a mole of a compound is calculated
6. Using dimensional analysis (and COMPLETE units), perform mole conversions between mass, moles,
representative particles, and volume at STP
7. Identify the volume of a quantity of gas at STP (STP = standard temperature and pressure)
8. Describe how to calculate the percent by mass of an element in a compound (= percent composition)
9. Calculate percent composition from a substances formula, name, or mass of components; calculate mass the
components of a compound from percent composition
10. Interpret the empirical formula
11. Distinguish between empirical and molecular formulas
12. Determine the empirical and/or molecular formula if given mass or percent composition
13. Use Quantitative Analysis to determine the empirical formula of a compound and/or hydrate
14. If given the molarity and volume of a solution, determine the number of moles of solute and vice versa
KEY POINT: you must be able to write a chemical formula correctly in order to correctly perform calculations
Ch 12 Objectives
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Explain how balanced equations apply to both chemistry and everyday life
Interpret balanced chemical equations in terms of moles, representative particles, mass, and gas volume at STP
Identify the quantities that are always conserved in chemical reactions
Explain what is meant by “stoichiometric proportions”
Construct mole ratios from balanced chemical equations and apply these ratios in stoichiometric calculations
(interpretation: you must be able to write a balanced formula equation from reactant names or formulas, then
use this equation for all calculations)
Calculate stoichiometric quantities from balanced chemical equations using units of moles, mass, representative
particles, and volumes of gases at STP
Identify the limiting reagent in a reaction
Identify and distinguish from one another theoretical yield, actual yield, and percent yield
Calculate the theoretical yield, actual yield, or percent yield given appropriate information
Use Quantitative Analysis to determine stoichimetric proportions, limiting reagent, and percent yield
Calculate the amount of excess reagent used and remaining (once the limiting reactant is determined).