Question

why does the blue colour of copper sulphate change when a piece of iron is dropped into it

Answer 1

Hey!!

The colour of copper Sulphate solution changes into green when an iron nail is dropped in it.

This is because, Iron which is more reactive than Copper displaces it and forms Iron Sulphate.
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Hope it helps!

Answer 2

Answer:

The colour of copper Sulphate solution changes into green when an iron nail is dropped in it.

Explanation:

This is because Iron which is more reactive than Copper displaces it and forms Iron Sulphate