Question

why does the colour of copper sulphate solution change when an iron nail is dipped​

Answer 1

Answer:

When an iron nail dipped in the copper sulphate solution than iron displaces copper from the copper sulphate because iron is more reactive than copper.

Therefore the colour of the copper sulphate solution changes.

Answer 2

Answer:

The color of copper sulphate solution changes from blue to pale green when an iron nail is dipped in it because iron displaces copper as iron is more reactive than copper.