iron nail was dipped into a salt solution . after sometime a reddish- brown deposition was seen .what could be the salt solution

The salt solution should be copper sulphate (CuSO₄). Iron displaces copper from its salt solution as a result of which a reddish-brown layer of Cu is deposited on iron nail. The reaction is as follows:
$Fe\left(s\right) + CuS{O}_4\left(aq\right) \to FeS{O}_4\left(aq\right) +Cu\left(s\right)$