Question

What changes in the colour of iron nails and copper sulphate solution do you observe after keeping the iron nails dipped in copper sulphate solution for about 30 minutes?

Answer 1

When iron nail (Fe) is kept in copper sulphate ($CuS{O}_4$), reaction takes place between them. As iron is more reactive than copper, it can replace copper from $CuS{O}_4$.

$Fe+CuS{O}_4\to FeS{O}_4+Cu$

$CuS{O}_4$ is in blue in colour, while $FeS{O}_4$ is in light green colour.

So, there will be a change in the composition and colour of the solution (from blue to light green). And deposition of copper layer on surface of the nail.