A laboratory assistant needs 0.100 mol of aluminium oxide, Al2O3\mathrm{Al_2O_3}Al2O3, for an experiment.
Relative atomic mass (ArA_rAr): Al = 27.0 O = 16.0
What mass of aluminium oxide should the assistant weigh out?
4.30 g4.30\,\mathrm{g}4.30g
102 g102\,\mathrm{g}102g
10.2 g10.2\,\mathrm{g}10.2g
7.00 g7.00\,\mathrm{g}7.00g
134 exam-style questions on OCR GCSE Chemistry 3.1 Introducing chemical reactions, covering 3.1.1 Writing formulae and balanced chemical equations, 3.1.2 Formulae of compounds from ions, and state symbols, 3.1.3 Conservation of mass and observed changes in mass, 3.1.4 Half equations and balanced ionic equations, 3.1.5 The mole and the Avogadro constant, and 3.1.6 Stoichiometry, limiting reactants and reacting masses. Each one has a worked solution and a mark scheme showing where the marks go.