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

It shows a displacement reaction between copper and silver nitrate. Copper displaces nitrate from silver nitrate and forms copper nitrate and silver. So, a black layer on copper plate comes

Answer 2

The reason is that there is a electrolysed  displacement between copper and silver nitrate. The copper plate displaces nitrate from silver nitrate and forms CuNO3 copper nitrate and Ag+ that is argentum ion. So, a black layer on copper plate forms due to presence of copper nitrate.