What happens if a iron nail dipped in copper sulphate solution

Copper Sulphate Solution (CuSO4) is blue in colour. When iron nail is placed in it, we can observe the following:

1) reddish brown deposits on iron (these are of Copper)

2) colour of the solution turns from blue to light green.

The formula for this reaction is: Fe + CuSO4 --> FeSO4 + Cu

Here, Fe is more reactive than Cu. So Fe displaces Cu to form Iron Sulfate and Copper