Question

put two to three iron nails in the blue solution of copper sulphate and after 15 to 20 minutes the colour explain​

Answer 1

Answer:

the colour of the iron nail becomes brownish and the blue colour of the copper sulphate fades .

Explanation:

this happens due to displacement reaction in which a less reactive metal displaces the more reactive metal .

the following reaction takes place

Fe +CuSo4 gives FeSo4 +Cu