What is the percent yield of ZnCl2 when 18.0 g of Zn reacts with excess HCl and 29.3 g ZnCl2 is produced?

Question

Zn + 2HCl = ZnCl2 + H2

Answer 1

The percent yield can be calculated using this formula:

% yield = actual yield / theoretical yield x 100

The actual yield (29.3 g) is given in the problem. However, the theoretical yield - also known as the maximum yield - must be calculated based on the amount of the given reactant.

18.0 g Zn x 1 mol Zn / 65.38 g Zn x 1 mol ZnCl₂ / 1 mol Zn x 136.29 g ZnCl₂ / 1 mol ZnCl₂ = 37.5 g ZnCl₂

% yield = 29.3 g ZnCl₂ / 37.5 ZnCl₂ x 100 = 78.1%