Formulae and equations

theoretical yield

maximum possible mass of a product, assuming complete reaction and no losses

actual yield

actual mass obtained

percentage yield

100 x the actual yield divided by the theoretical yield

3 reasons why mass of a reaction product may be less than the maximum possible

reaction is reversible and so may not be complete

side-reactions that lead to other unwanted products

product may need to be purified, which may result in loss of product

1 tonne in g

1 × 10^6 g

Reaction with 100% atom economy

Addition reactions

Reaction with lower atom economies

Elimination and substitution

Multistep reactions

Atom economy equation 

molar mass of the desired product / sum of the molar masses of all products 

X 100