Question

A % yield < 100 can be explained by losses and side reactions. how could you accountn for a % yield > 100

Answer 1

Percent yield is expected to be less than 100% because it is:

           Percent yield = [actual yield / theoretical yield] × 100

The theoretical yield is calcualted from the stoichiometry of the chemical equation, then the actual yield cannot be greater than the theoretical yield.

A theoretical yield greater than 100% is indication of an error.

Two errors can be thought:

- A wrong measurement of the amounts of reactants or products

- The presence of impurities in the reactants that lead to the actual mass is greater than the mass if the reactant is pure.