Limiting and Excess Reactants

Front

What is a limiting reactant?

Back

The limiting reactant is the substance that is used up first 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 required by the balanced equation.

Front

What happens to the excess reactant in a chemical reaction?

Back

The excess reactant is the substance that remains after the reaction has gone to completion; it is not completely used up.

Front

Why is it important to identify the limiting reactant?

Back

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

Front

In the reaction 1 Cheese + 2 Bread -> 1 grilled cheese, how many grilled cheeses can you make with 26 slices of bread and 14 pieces of cheese?

Back

You can make 13 grilled cheeses.

Front

In the reaction P4 + 3O2 -> P4O6, what is the limiting reactant if you have 12 moles of P4 and 15 moles of O2?

Back

The limiting reactant is O2.

Front

What is the role of stoichiometry in identifying limiting reactants?

Back

Stoichiometry allows you to calculate the amounts of reactants and products involved in a reaction, helping to identify the limiting reactant.

Front

If 2 moles of aluminum and 2 moles of chlorine are reacted in the equation 2 Al + 3 Cl2 -> 2 AlCl3, which is the limiting reactant?

Back

The limiting reactant is Cl2.

Front

What is the relationship between limiting reactants and product yield?

Back

The limiting reactant directly affects the product yield; the amount of product formed is based on the amount of the limiting reactant.

Front

Define excess reactant.

Back

An excess reactant is a reactant that remains after a chemical reaction has completed because there was more of it than needed.