Question

A copper plate was dipped into a solution of silver nitrate after sometime a black layer was observed on the surface of copper plate state the reason write the chemical equation involved

Answer 1

a black layer is due to the displacement reaction. the black layer is the copper deposits. since copper is reactive than silver it displaces the silver from its salt solution. 

Answer 2

Copper is more reactive than silver and therefore it displaces silver from silver nitrate.

Cu + 2AgNO3 → Cu(NO3)2 + 2Ag