In the silver plating of copper, `K[Ag(CN)_(2)]` is used instead of `AgNO_(3)` . The reason is

Options

A. a thin voltage of Ag is formed on Cu
B. more voltage is required
C. `Ag^(+)` ions are completely removed form solution
D. less availabiliuty of `Ag^(+)` ions as Cu cannot displace Ag form `[Ag(CN)_(2)]^(-)` ion

Answer

D

Explanation

Ag can't be displaces by Cu from the complex ion `[Ag(CN_(2))]^(-)` . Thus, there is gradual but steady conc. Of `Ag^(+)` for plating.