Question

Why does the the colour of copper sulphate changes when an iorn nail is dipped in it ? Write two observations

Answer 1

Iron is more reactive than copper. When a more reactive metal is placed in a salt solution of a lesser reactive metal, it removes the lesser reactive metal from its salt solution. This is called a displacement reaction.

Hence, the solution becomes Ferrous Sulphate and turns green, and Copper appears as a reddish-brown coating on the iron nail.