Understanding Limiting Reagents, Theoretical Yield, and Percent Yield

What is the limiting factor in the peanut butter and jelly sandwich analogy?

• Hunger

• Bread

• Jelly

• Peanut butter

In a chemical reaction, what is the limiting reagent?

• The catalyst used

• The product formed

• The reactant that runs out first

• The reactant that is in excess

Why can't mass alone determine the limiting reagent in a chemical reaction?

• Chemical equations are based on moles, not mass

• Mass is only used for products

• Mass is always conserved

• Mass is irrelevant in chemistry

How do you determine the theoretical yield in a chemical reaction?

• By calculating the percent yield

• By measuring the actual yield

• By using the limiting reagent

• By using the excess reagent

What is the first step in determining the limiting reagent?

• Measure the actual yield

• Convert masses to moles

• Calculate percent yield

• Identify the products

What is the significance of stoichiometric conversions in determining the limiting reagent?

• They help identify the excess reagent

• They are not necessary for determining the limiting reagent

• They are used to calculate the percent yield

• They allow conversion between reactants and products

What does percent yield express in a chemical reaction?

• The theoretical yield

• The efficiency of a synthetic procedure

• The purity of the product

• The amount of reactants used

Why is the actual yield often less than the theoretical yield?

• Due to the use of impure reactants

• Because actual yield is measured in a lab

• Because theoretical yield is always overestimated

• Due to errors in the chemical reaction

How is percent yield calculated?

• Theoretical yield minus actual yield, multiplied by 100%

• Theoretical yield divided by actual yield, multiplied by 100%

• Actual yield divided by theoretical yield, multiplied by 100%

• Actual yield plus theoretical yield, divided by 2

What is the percent yield if the actual yield is 9.5 grams and the theoretical yield is 12 grams?

• 85.3%

• 100%

• 79.2%

• 91.7%