Question

A solution of silver nitrate should only be stirred with a spoon made of ­­­__________ metal.

Answer 1

1. Copper ($\mathrm{Cu}$) metal is more reactive than silver ($\mathrm{Ag}$) metal thus, when a copper spoon is stirred in silver nitrate (${\mathrm{AgNO}}_3$) solution for some time, the solution turns blue as copper displaces silver from Silver nitrate to form silver metal ($\mathrm{Ag}$) and Cupric nitrate ( $\mathrm{Cu}{\left({\mathrm{NO}}_3\right)}_2$).
2. Reaction: $$\begin{gathered} \mathrm{Cu}\left(\mathrm{s}\right)+2{\mathrm{AgNO}}_3\left(\mathrm{aq}\right)\to \mathrm{Cu}{\left({\mathrm{NO}}_3\right)}_2\left(\mathrm{aq}\right)+2\mathrm{Ag}\left(\mathrm{s}\right) \\ (\mathrm{Copper}\mathrm{metal})(\mathrm{Silver}\mathrm{nitrate})(\mathrm{Copper}\mathrm{nitrate})(\mathrm{Silver}\mathrm{metal}) \end{gathered}$$.

Therefore, a solution of silver nitrate should only be stirred with a spoon made of ­­­Copper ($\mathbf{Cu}$) metal.