Limiting and Excess Reactants

Front

What is a limiting reactant?

Back

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

Front

How do you identify the limiting reactant in a reaction?

Back

To identify the limiting reactant, compare the mole ratio of the reactants used in the reaction to the mole ratio from the balanced equation.

Front

What is an excess reactant?

Back

An excess reactant is a substance that remains after a chemical reaction has completed because it was not completely used up.

Front

In the reaction 4NH₃ + 6NO → 5N₂ + 6H₂O, if you have 10 moles of NH₃ and 30 moles of NO, which is the limiting reactant?

Back

NH₃ is the limiting reactant.

Front

In the reaction P₄ + 3O₂ → P₄O₆, how many moles of P₄O₆ can be produced from 3 moles of P₄ and 6 moles of O₂?

Back

2 moles of P₄O₆ can be produced.

Front

If you have 26 slices of bread and 14 pieces of cheese, how many grilled cheeses can you make with the recipe 1 Cheese + 2 Bread?

Back

You can make 13 grilled cheeses.

Front

What happens to the limiting reactant during a chemical reaction?

Back

The limiting reactant is used up first during the reaction.

Front

What is the mole ratio in a balanced chemical equation?

Back

The mole ratio is the ratio of moles of reactants and products as indicated by the coefficients in a balanced chemical equation.

Front

Why is it important to identify the limiting reactant in a chemical reaction?

Back

Identifying the limiting reactant is important because it determines the maximum amount of product that can be formed.

Front

What is stoichiometry?

Back

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