Chemistry · May / June 2022 · Paper 11 · Question 3

Two samples of a colourless solution are tested separately with aqueous sodium hydroxide, NaOH(aq), and aqueous ammonia, NH$_3$(aq), and the results are recorded. • A white precipitate is formed with two drops of NaOH(aq). This precipitate dissolves in an excess of NaOH(aq). • A white precipitate is formed with two drops of NH$_3$(aq). This precipitate dissolves in an excess of NH$_3$(aq). What can be deduced from these results?

1. AThe anion present is Cl$^-$.
2. BThe anion present is not Cl$^-$.
3. CThe cation present is Al$^{3+}$.
4. DThe cation present is Zn$^{2+}$.

As printed in the paper