RPAL Percent Yield

Question 1

What is percent yield?

Accepted Answer

The ratio of actual yield to theoretical yield expressed as a percentage

Answer

Percent yield = (actual yield / theoretical yield) × 100%, measuring how efficient a reaction was in the lab.

Question 2

What is the formula for percent yield?

Accepted Answer

(Actual yield ÷ Theoretical yield) × 100%

Answer

Percent yield is calculated by dividing the actual yield by the theoretical yield and multiplying by 100%.

Question 3

If the theoretical yield is 50 g and the actual yield is 40 g, what is the percent yield?

Accepted Answer

80%

Answer

(40 g / 50 g) × 100% = 80% yield.

Question 4

Why is percent yield almost always less than 100%?

Accepted Answer

Because of side reactions, product loss during purification, and incomplete reactions

Answer

Real reactions lose product through side reactions, handling losses, and incomplete conversion, making 100% yield essentially unattainable.

Question 5

A percent yield greater than 100% indicates what?

Accepted Answer

An error — possibly impure product or incorrect theoretical yield calculation

Answer

A percent yield over 100% is physically impossible and signals experimental error such as product contamination or a miscalculated theoretical yield.

RPAL - Reactants, Products, and Leftovers Practice Test