A stock list gives the formula Al3NO3\mathrm{Al_{3}NO_{3}}Al3NO3 for aluminium nitrate. Aluminium nitrate contains Al3+\mathrm{Al^{3+}}Al3+ ions and NO3−\mathrm{NO_{3}^{-}}NO3− ions.
Which correction should be made to the stock list?
Replace the subscript 3 after aluminium with the ion charges, giving Al3+NO3−\mathrm{Al^{3+}NO_{3}^{-}}Al3+NO3−
Move the subscript 3 from aluminium to outside brackets around nitrate, giving Al(NO3)3\mathrm{Al(NO_{3})_{3}}Al(NO3)3
Remove the subscript 3 from aluminium and make no other change, giving AlNO3\mathrm{AlNO_{3}}AlNO3
Add brackets around nitrate but leave the subscript 3 after aluminium, giving Al3(NO3)\mathrm{Al_{3}(NO_{3})}Al3(NO3)
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.