Question

When an iron nail is put into a beaker containing copper sulphate solution, the blue colour of the solution slowly changes to green
a) Why does the colour of the solution change?

Answer 1

a)

1. Copper sulphate solution is blue and acquires a sea-green colour when an iron nail is dropped into it. This is because iron sulphate is formed when copper sulphate reacts with iron.
2. Fe(s) + CuSO4(aq) → FeSO4(aq) + Cu(s)

Answer 2

the color of the solution changes due to the copper sulphate reacts with iron

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