Question

Question #8a5f1

Answer 1

`Na_2ZnO_(2(aq))+2HCl_((aq))rarrZnO_((s))+H_2O_((l))+NaCl_((aq))`

Explanation:

The ions present in sodium zincate are `Na^(+)` and zincate which is `ZnO_2^(2-)`.

Zinc oxide is amphoteric, which means that it can react react with both acid and base.

Sodium zincate is formed if zinc oxide is treated with an alkali such as `NaOH`:

`ZnO_((s))+2NaOH_((aq))rarrNa_2ZnO_(2(aq))+H_2O_((l))`

We can reverse the process by adding acid:

`Na_2ZnO_(2(aq))+2HCl_((aq))rarrZnO_((s))+H_2O_((l))+NaCl_((aq))`

The zincate ion is written more precisely as `Zn(OH)_(4(aq))^(2-)`.

Adding acid would remove 2 `OH^-` ions to leave a white precipitate of zinc hydroxide `Zn(OH)_(2(s)`.