Limiting reactant

Definition

The limiting reactant in a chemical reaction is the substance that is entirely consumed first, limiting the amount of products formed. It determines the maximum yield of the reaction.

5 Must Know Facts For Your Next Test

1. The limiting reactant can be identified by comparing the mole ratio of available reactants to the mole ratio in the balanced equation.
2. Calculating the limiting reactant involves converting masses of reactants to moles and using stoichiometric coefficients.
3. The reactant that produces the least amount of product is the limiting reactant.
4. Once the limiting reactant is used up, no further product can form, even if other reactants are still available.
5. Knowing the limiting reactant allows for accurate calculation of theoretical yield and percent yield.

Review Questions

• How do you determine which reactant is the limiting one in a chemical reaction?
• Why is it important to identify the limiting reactant when calculating theoretical yield?
• What happens to a chemical reaction once all of its limiting reactant has been consumed?

Related terms

Stoichiometry:

The calculation of relative quantities of reactants and products in chemical reactions.

Theoretical Yield:

The maximum amount of product that can be formed from given amounts of reactants, based on stoichiometric calculations.

Excess Reactant:

A substance that remains after a chemical reaction has completed because there was more than enough to completely react with the limiting reactant.