RPAL Percent Yield 3

Question 1

For a reaction producing aspirin, if the theoretical yield is 3.00 g and 2.64 g is collected, what is the percent yield?

Accepted Answer

88%

Answer

114%

Answer

88.8 g

Answer

12%

Question 2

A reaction yields 0.45 mol of product but the theoretical yield is 0.50 mol. What is the percent yield?

Accepted Answer

90%

Answer

10%

Answer

111%

Answer

45%

Question 3

Which of the following is a common source of percent yield less than 100% in lab experiments?

Accepted Answer

Product left on glassware during transfer

Answer

Using too large a beaker

Answer

Measuring mass before the reaction

Answer

Adding reactants in the correct order

Question 4

If a reaction has multiple steps, each with 90% yield, what is the overall yield after two steps?

Accepted Answer

81%

Answer

90%

Answer

45%

Answer

180%

Question 5

A reaction with a theoretical yield of 10 g gives only 2 g of product. What is the percent yield, and how might a chemist improve it?

Accepted Answer

20%; improve by minimizing side reactions and product loss

Answer

80%; this is already a good yield

Answer

20%; use more excess reagent to force more product

Answer

50%; the calculation shows average performance

Question 6

Which expression correctly rearranges percent yield to find actual yield?

Accepted Answer

Actual yield = (percent yield / 100) × theoretical yield

Answer

Actual yield = theoretical yield / (percent yield × 100)

Answer

Actual yield = percent yield + theoretical yield

Answer

Actual yield = theoretical yield − percent yield