RPAL Percent Yield 2

Question 1

A reaction has a theoretical yield of 25 g and a percent yield of 72%. What is the actual yield?

Accepted Answer

18 g

Answer

Actual yield = (72/100) × 25 g = 18 g.

Question 2

What does a percent yield of 95% tell a chemist?

Accepted Answer

5% of the expected product was lost or not formed

Answer

A 95% yield means 5% of the theoretical product was lost, which is a very good result in synthetic chemistry.

Question 3

If 3.6 g of product is collected from a reaction with a theoretical yield of 4.0 g, what is the percent yield?

Accepted Answer

90%

Answer

(3.6 / 4.0) × 100% = 90% yield.

Question 4

In industrial chemistry, why is maximizing percent yield important?

Accepted Answer

It reduces waste and lowers production costs per unit of product

Answer

Higher percent yield means less raw material is wasted and more product is obtained per run, directly reducing manufacturing costs.

Question 5

What is the theoretical yield if the actual yield is 12 g and the percent yield is 60%?

Accepted Answer

20 g

Answer

Theoretical yield = actual yield / (percent yield / 100) = 12 / 0.60 = 20 g.

RPAL - Reactants, Products, and Leftovers Practice Test