applications of stoichiometry

Question 1

Limiting Reagent

Answer 1

• one reactant that will be used up or consumed first

- it limits the amount of product that can be formed in a reaction

Question 2

Excess Reagents

Answer 2

The reactants that remain after all the limiting reagent is used up

Question 3

With problems involving the determination of the limiting reagent, keep in mind two things:

Answer 3

1. all comparisons of reactants must be done in units of moles. Gram - to - gram comparisons will be useless and may even be misleading
2. It is not the absolute mole quantities of th reactants that determine which reactant is the limiting reagent. Rather, the rate at which the reactants are consumed (the stoichiometric ratio of the reactants), combined with the absolute mole quantities determines which reactant is the limiting reagent

Question 4

Yield

Answer 4

refers to either the amount of product predicted (theoretical yield) or actually obtained (raw or actual yield) when a reaction is carried out

Question 5

Theoretical yield

Answer 5

the maximum amount of product that can be generated as predicted form the balanced equation, assuming that all the limiting reactant is consumed, no side reactions have occurred and the entire product has been collected.

rarely ever attained through the actual chemical reaction

Question 6

Actual yield

Answer 6

the amount of product one actually obtains during the reaction

Question 7

% yield =

Answer 7

(actual yield/theoretical yield) x 100