Question

A copper plate was dipped into a solution silver nitrate. After sometimes, a black layer was observed on the surface of copper plate. State the reason for it and write chemical equation of the reaction involved

Answer 1

When the copper plate is dipped in silver nitrate solution then a chemical reaction takes place,

• Cu + AgNO₃ → Cu(NO₃)₂ + Ag

Hence, this is a displacement reaction where more reactive metal (Copper) displaces less reactive metal (Silver) from it's compound (AgNO₃)

Therefore a new compound, Cu(NO₃)₂ is formed in this reaction which has a black colour deposit on plate.

Answer 2

Answer :-

Black layer was deposited due to the coating of silver because copper being more reactive than silver, displaced silver from silver nitrate solution.

$\sf 2AgNO_3(aq)+Cu \: \: \to \: \: Cu(NO_3)_2(aq)+2Ag(S)$