(a(i))[3]
Demonstrate by calculation that zinc oxide is in excess. $\text{ZnO}(s) + 2\text{HCl}(aq) \rightarrow \text{ZnCl}_2(aq) + \text{H}_2\text{O}(l)$ A 3.50 g sample of zinc oxide is placed into 50.0 cm$^3$ of 1.20 mol dm$^{-3}$ hydrochloric acid.
(a(ii))[1]
State why it matters to use an excess of zinc oxide in this preparation.
(a(iii))[1]
Suggest how the extra zinc oxide is separated from the reaction mixture so that only aqueous zinc chloride remains.
(b)[1]
Barium sulfate is an insoluble salt, so it is made by a precipitation reaction. Name two aqueous solutions that can be mixed to form a barium sulfate precipitate.
(c(i))[1]
State the acid and the alkali used to make sodium nitrate.
(c(ii))[1]
Name the experimental method used to prepare neutral aqueous sodium nitrate.