Question

when an iron knife is dipped in a solution of copper sulphate a reddish brown layer form​

Answer 1

Explanation:

Because the iron from the knife displaces the copper from the solution (as iron is more reactive than copper )and forms iron sulphate solution which is green in colour. When an iron knife is dipped is copper sulphate solution, after some time we'll see it has turned light green (from blue) in colour.

Answer 2

Answer:

Heya!!Here is your answer friend ⤵⤵

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⏪When an iron knife is dipped in a solution of copper sulphate , the following reaction takes place ,

CuSO4 +. Fe ------------FeSO4 + Cu.

➡It is a DISPLACEMENT REACTION. Iron being more reactive than copper displaces it from its aqueous solution. The color of the solution changes to light green and a reddish brown coat is deposed on iron.

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Hope it helps you ✌✌