Limiting/Excess Reactants

Front

What is a limiting reactant?

Back

The reactant that is completely consumed in a chemical reaction, limiting the amount of product formed.

Front

What is an excess reactant?

Back

A reactant that is not completely consumed in a chemical reaction and remains after the reaction is complete.

Front

How do you determine the limiting reactant in a reaction?

Back

By comparing the mole ratios of the reactants used in the balanced chemical equation to the amounts available.

Front

What is a mole ratio?

Back

The ratio of moles of one substance to the moles of another substance in a balanced chemical equation.

Front

What is the balanced equation for the reaction of NH3 and NO?

Back

4NH3 + 6NO → 5N2 + 6H2O.

Front

If you have 10 moles of NH3 and 30 moles of NO, which is the limiting reactant?

Back

NH3 is the limiting reactant.

Front

What happens to the excess reactant after a reaction?

Back

It remains unreacted after the reaction has completed.

Front

In the reaction 2C + 1M + G2 → C2MG2, how many S'mores can be made with 5 M, 9 C, and 9 G?

Back

4 S'mores can be made.

Front

What is stoichiometry?

Back

The calculation of reactants and products in chemical reactions based on the balanced equation.

Front

Why is it important to identify limiting and excess reactants?

Back

To predict the amount of product formed and to understand the efficiency of the reaction.