Copper sulphate solution does not react with

${\mathrm{C}\mathrm{u}\mathrm{S}\mathrm{O}}_4$will react with elements placed above it in electrochemical series and it would not react with elements places below it in electrochemical series.

∴ ${\mathrm{C}\mathrm{u}\mathrm{S}\mathrm{O}}_4$ reacts with Zn and Fe placed above it.

${\mathrm{C}\mathrm{u}\mathrm{S}\mathrm{O}}_4$ + Fe → ${\mathrm{F}\mathrm{e}\mathrm{S}\mathrm{O}}_4\mathrm{ }$ + Cu

${\mathrm{C}\mathrm{u}\mathrm{S}\mathrm{O}}_4$ + Zn → ${\mathrm{Z}\mathrm{n}\mathrm{S}\mathrm{O}}_4$ + Cu

∴ ${\mathrm{C}\mathrm{u}\mathrm{S}\mathrm{O}}_4$ does not react with Ag, placed below it.

${\mathrm{C}\mathrm{u}\mathrm{S}\mathrm{O}}_4$ + Ag → no reaction.