Limiting Reagents and Percent Yield Quiz

What is the limiting reagent in a chemical reaction?

• The substance that is totally consumed when the chemical reaction is complete.

• The substance that remains when the reaction stops.

• The substance with the highest molar mass in the reaction.

• The substance you have the most of when the reaction is complete.

Tags

NGSS.HS-PS1-7

If 5.0 grams of A react with 3.0 grams of B to produce C, and after the reaction, there are still 1.0 grams of B left, which is the limiting reagent?

• A

• B

• C

• Both A and B

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NGSS.HS-PS1-7

How do you determine the excess reagent in a chemical reaction?

• By calculating which reagent has the highest molar mass.

• By identifying the reagent with the smallest coefficient in the balanced reaction equation.

• By calculating the amount of each reagent left over after the reaction has gone to completion.

• By determining which reagent has the highest boiling point.

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NGSS.HS-PS1-7

What is percent yield?

• The ratio of the actual yield to the theoretical yield, multiplied by 100%.

• The percentage of the reactant that remains unreacted.

• The percentage of the product that decomposes during the reaction.

• The ratio of the theoretical reactant to the theoretical yield, multiplied by 100%.

Tags

NGSS.HS-PS1-7

If the theoretical yield of a reaction is 10 grams and the actual yield is 7 grams, what is the percent yield?

• 30%

• 70%

• 100%

• 130%

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NGSS.HS-PS1-7

• A

• B

• C

• Neither A nor B

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NGSS.HS-PS1-7

What happens to the excess reagent after the reaction has gone to completion?

• It continues to react until it is also consumed.

• It is automatically converted into the product.

• It remains in the reaction mixture.

• It disappears without a trace.

Tags

NGSS.HS-PS1-7

How can the percent yield of a reaction be increased?

• Speeding up the reaction.

• By adding more of the limiting reagent.

• By purifying the reactants before the reaction.

• By optimizing reaction conditions to reduce the formation of by-products.

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NGSS.HS-PS1-5

NGSS.HS-PS1-6

If 50 grams of reactant A reacts with 50 grams of reactant B to produce 80 grams of product C, and the theoretical yield of C is 100 grams, what is the percent yield of C?

• 50%

• 80%

• 100%

• 120%

Tags

NGSS.HS-PS1-7

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

• Determining the molar mass of each reactant.

• Converting grams of reactants to moles.

• Calculating the molar mass of the products.

• Calculating the molar ratio of reactants from the balanced chemical equation.