A chemist analyses two ionic compounds containing an unknown metal, M. The first compound is a chloride with the formula MCl3\mathrm{MCl_{3}}MCl3. The metal ions have the same charge in both compounds. The second compound contains sulfate ions, SO42−\mathrm{SO_{4}^{2-}}SO42−.
What formula should the chemist record for the second compound?
M3(SO4)2\mathrm{M_{3}(SO_{4})_{2}}M3(SO4)2
M(SO4)3\mathrm{M(SO_{4})_{3}}M(SO4)3
M2(SO4)2\mathrm{M_{2}(SO_{4})_{2}}M2(SO4)2
M2(SO4)3\mathrm{M_{2}(SO_{4})_{3}}M2(SO4)3
119 exam-style questions on Edexcel GCSE Chemistry 2.3 Ionic bonding, covering 2.3.1 Ions and the formation of ionic bonds, 2.3.2 Naming and deducing formulae of ionic compounds, and 2.3.3 Giant ionic lattices. Each one has a worked solution and a mark scheme showing where the marks go.