Question

Why does colour of copper sulphate solutions change when an iron nail is dipped in it?

Answer 1

copper sulphate changes its colour when iron is dipped because iron displaces copper and the solution becomes ferrous sulphate. thus the blue colour of copper sulphte changes to green colour

Answer 2

copper sulfate changes its colour when iron is dipped because iron displaces copper in the solution of copper sulfate to become ferrous sulfate which is green in colour