Write chemical formulae of the sulphates of Aluminium, Ammonium and Zinc.

(a) Chemical formula of Aluminium Sulphate:

$\text{Al}^{3+} \space \text{SO}$4^{2-} \\[1em] \overset{\phantom{3}{3}}{\text{Al}} \space {\swarrow}\mathllap{\searrow} \space \overset{2}{\text{SO}4} \Rightarrow \underset{\phantom{2}{2}}{\text{Al}} \space {\swarrow}\mathllap{\searrow} \underset{\phantom{3}{3}}{\text{SO}4} \\[1em] \text{Al}2\text{(SO}4)3

∴ Chemical formula of Aluminium Sulphate is Al₂(SO₄)₃

(b) Chemical formula of Ammonium Sulphate:

$\text{NH}$4^{+} \space \text{SO}4^{2-} \\[1em] \overset{\phantom{3}{1}}{\text{NH}4} \space {\swarrow}\mathllap{\searrow} \space \overset{2}{\text{SO}4} \Rightarrow \underset{\phantom{2}{2}}{\text{NH}4} \space {\swarrow}\mathllap{\searrow} \underset{\phantom{3}{1}}{\text{SO}4} \\[1em] \text{(NH}4)2\text{SO}_4

∴ Chemical formula of Ammonium Sulphate is (NH₄)₂SO₄

(c) Chemical formula of Zinc Sulphate:

$\text{Zn}^{2+} \space \text{SO}$4^{2-} \\[1em] \text{Dividing by H.C.F. it becomes} \\[1em] \text{Zn}^{1+} \space \text{SO}4^{1-}\\[1em] \overset{\phantom{22}{1}}{\text{Zn}} \space {\swarrow}\mathllap{\searrow} \space \overset{1}{\text{SO}4} \Rightarrow \underset{\phantom{2}{1}}{\text{Zn}} \space {\swarrow}\mathllap{\searrow} \underset{\phantom{2}{1}}{\text{SO}4} \\[1em] \text{ZnSO}_4

∴ Chemical formula of Zinc Sulphate is ZnSO₄