Question

Why does colour of copper sulphate solution change when an iron nail is dipped in it ? write a balanced chemical equation for same.

Answer 1

Colour of copper sulphate solution is blue in colour.
Iron being highly reactive element than copper which displaces the copper from its salt solution...

When this happen , two things are observed

=> Colour of the copper sulphate solution ( blue colour ) turns light green which is nothing just a iron sulphate solution..

=> Copper get deposited over the iron nail due to which iron nail turns in brownish colour..

This type of reaction is called displacement reaction in which highly reactive element displaces the least reactive element from its salt solution...

Chemical equation
=================
CuSO4 ( aq ) + Fe ( s )
--> FeSO4 ( aq ) + Cu ( s )
( equation is already balanced )

Answer 2

This is your correct answer