what is the theoretical yield and percent yield?

Question

 When 50.5 grams of KMnO₄ is used, what is the theoretical yield of MnCl₂? If only 36.2 grams of MnCl₂ are obtained, what is the percent yield?

Answer 1

To even begin to answer this question, we need to know the balanced equation:

2KMnO₄  + 16HCl ==> 2KCl + 2MnCl₂ + 8H₂O + 5Cl₂ ... balanced equation

Theoretical yield = 50.5 g KMnO₄ x 1 mol/158 g x 2 mol MnCl₂/2 mol KMnO₄ x 126 g/mol = 40.3 g MnCl₂

% yield = actual yield/theoretical yield (x100%) = 36.2 g/40.3 g (x100%) = 89.8%