Relative atomic masses: Li = 7, B = 11, N = 14, Al = 27
The Avogadro constant = 6.02 × 1023 per mole
A silver ring contains 0.200 mol of silver. Use the Avogadro constant to work out how many silver atoms are in the ring. Give your answer to three significant figures.
A sample contains 0.500 mol of nitrogen molecules, N2\mathrm{N_2}N2. Calculate the mass of the sample.
A student compares a 1.40 g sample of lithium with a 2.20 g sample of boron.
Calculate the amount, in moles, of atoms in each sample. Use your answers to determine whether the two samples contain the same number of atoms.
A piece of aluminium foil contains 1.204 × 1024 aluminium atoms. Calculate the mass of the foil.
142 exam-style questions on Edexcel GCSE Chemistry 2.6 Calculations involving masses, covering 2.6.1 Relative formula mass and percentage composition, 2.6.2 Empirical and molecular formulae, 2.6.3 Conservation of mass, 2.6.4 Reacting masses and concentration in g dm⁻³, 2.6.5 The mole and the Avogadro constant, and 2.6.6 Limiting reactants and stoichiometry. Each one has a worked solution and a mark scheme showing where the marks go.