1. Ch. 9 Stoichiometry
Stoichiometry is a branch of chemistry that deals with the mass relationships of elements in compounds and the mass relationships between reactants and products in chemical reactions.
2 Types of Stoichiometry
1. Composition Stoichiometry – is the mass relationships of elements in chemical compounds.
Ex. Molar mass of Li is grams

2. 2. Reaction Stoichiometry – is the mass relationship among reactants and products of a chemical reaction.
Ex. NaCl + H2O  HCl + NaOH
58.44g g g g
4 Reaction – Stoichiometry Problems
1. Mole to Mole
2. Mass to Mass
3. Mole to Mass
4. Mass to Mole

3. EXAMPLES ???
Sample Problems 9.1 – 9.5
Limiting Reactant is the reactant that limits the amount of the other reactants that can combine, and the amount of products formed in a chemical reaction.
Excess Reactant is the substance that is not used up completely in a reaction.
Ex. If a bus holds 50 people and 60 are waiting to ride the bus, 10 will be left in excess.
Sample problems 9.6 – 9.7

4. Percent Yield is the ratio of the actual yield to theoretical yield times 100%.
(Actual yield / Theoretical yield) X 100%
Theoretical yield is the maximum amount of product that can be produced from a given amount of reactant.
Actual yield is the measured amount of a product obtained from the product of a reaction.
Sample Problem 9.8