Question

$Zn$ and $Ag$ can be separated from each other by
(1) distillation
(2) heating with conc. $NaOH$
(3) fractional distillation
(4) treating with dil. $HNO _{3}$

• A. 1, 2 and 3 are correct
• B. 1 and 2 are correct
• C. 2 and 4 are correct
• D. 1 and 3 are correct

Answer 1

Answer: (B)

Boiling point of $Zn$ is $1180\, K$ and melting point of $Ag$ is $1234 \,K$, thus at the melting point of $Ag, Zn$ can be distilled off easily. Hence, these two are separated by distillation.
Moreover, only $Zn$ reacts with $NaOH$ and form sodium zincate.
$Zn +2 NaOH \longrightarrow Na _{2} ZnO _{2}+ H _{2}$