Aluminium nitrate contains Al3+\mathrm{Al^{3+}}Al3+ ions and NO3−\mathrm{NO_3^{-}}NO3− ions. A student writes its formula as AlNO3\mathrm{AlNO_3}AlNO3.
Which correction should the student make?
Add brackets around NO3\mathrm{NO_3}NO3 only, giving Al(NO3)\mathrm{Al(NO_3)}Al(NO3).
Write the ion charges in the formula, giving Al3+NO3−\mathrm{Al^{3+}NO_3^{-}}Al3+NO3−.
Add brackets around NO3\mathrm{NO_3}NO3 and a subscript 3, giving Al(NO3)3\mathrm{Al(NO_3)_3}Al(NO3)3.
Move the subscript 3 from within NO3\mathrm{NO_3}NO3 to Al\mathrm{Al}Al, giving Al3NO\mathrm{Al_3NO}Al3NO.
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.