Limiting Reagents & Percent Yield | Professor Dave Quiz

What is a limiting reagent in a chemical reaction?

• The substance that is most abundant

• The substance that is completely used up first

• The substance that is present in excess

• The substance that is least reactive

If you have 7 baloney and 10 bread, how many sandwiches can you make according to the given example?

• 7 sandwiches

• 3 sandwiches

• 5 sandwiches

• 10 sandwiches

Which of the following is NOT a correct step in determining the limiting reagent?

• Using stoichiometric ratios

• Assuming the reactant in lesser amount is always the limiting reagent

• Converting quantities to moles

• Calculating potential product amounts

What happens to the excess reagent in a reaction?

• It converts into a different compound

• It is completely used up

• It remains unused and is left over

• It disappears

In the example with baloney and bread, which is the limiting reagent?

• Baloney

• Neither is limiting

• Bread

• Both are limiting

What is percent yield?

• The ratio of actual yield to theoretical yield multiplied by 100

• The amount of product obtained from the reaction

• The theoretical maximum amount of product

• The difference between actual and theoretical yields

What does the theoretical yield represent?

• The maximum possible amount of product under perfect conditions

• The average yield from multiple experiments

• The actual amount of product obtained

• The minimum amount of product expected

If 10 grams of product were expected but only 8.4 grams were collected, what is the percent yield?

• 100%

• 78%

• 94%

• 84%

Why is it necessary to convert masses to moles when determining the limiting reagent?

• To compare quantities accurately

• Because moles are easier to measure

• Masses are always inaccurate

• Moles provide information on volume

What is the role of stoichiometric ratios in determining the limiting reagent?

• They determine the physical state of reactants

• They indicate the temperature required for the reaction

• They show how reactants combine in fixed proportions

• They are irrelevant to chemical reactions