WHAT LIMITS HOW MUCH REACTION CAN HAPPEN?
KEY IDEAS
The amount (in moles) of substances that can react with each other is limited by the amount of that one which is used up first. This is called the limiting reactant.
More reaction can happen if we add more of the limiting reactant. But no more reaction can result from addition of the other reactant – we would just have more of it left unreacted (we say “in excess”).
Stoichiometric calculations (How much of this reacts? How much of that is formed) must be based on the amount (in moles) of the limiting reagent present in the reaction mixture, taking into account the ratio of amounts that react with each other as indicated by the balanced chemical equation for the reaction.
More reaction can happen if we add more of the limiting reactant. But no more reaction can result from addition of the other reactant – we would just have more of it left unreacted (we say “in excess”).
Stoichiometric calculations (How much of this reacts? How much of that is formed) must be based on the amount (in moles) of the limiting reagent present in the reaction mixture, taking into account the ratio of amounts that react with each other as indicated by the balanced chemical equation for the reaction.
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ANSWERS