Question #8a5f1

1 Answer
Jun 29, 2015

Answer:

#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)#.