Formulae, reacting masses, yields and atom economy
SCISP Topic Book: Chemical Formulae and Equations
Although dated, this textbook is a good source of information and contains some good sets of questions that could be repurposed. The topics covered are mass, the mole and chemical formulae.
Moles and Reacting Masses
This website gives instructions on how to run a group activity reinforcing knowledge of calculating relative atomic mass, percentage of an element in a compound and masses of reactants and products. This is designed as a group activity but as there is a downloadable student sheet, it could equally be used individually as a homework activity.