The amount of a given product formed if all of the limiting reactant is consumed by the reaction.

• A. Actual yield
• B. Theoretical yield
• C. Percent yield
• D. Estimated yield

Answer: (B)

The main idea here is theoretical yield—the predicted maximum amount of product that could be formed if the limiting reactant is completely consumed and there are no losses. To get it, identify the limiting reactant from the balanced equation, then use the stoichiometric ratios to convert moles of that reactant into moles of the desired product, and finally convert to grams if needed.

For example, if the reaction is A + 2 B → C and B is the limiting reactant with 3 moles, the amount of product formed would be 3 moles B × (3 moles C / 2 moles B) = 4.5 moles of C. This is the theoretical yield.

This value serves as a benchmark to compare with the actual amount obtained in the lab (actual yield). The ratio of actual yield to theoretical yield, times 100%, gives the percent yield.