Question

When iron nail is dipped in a blue coloured copper sulphate solution, which of the following observations are not seen:

• A. the colour of the solution changes to red.
• B. the colour of the solution changes to green.
• C. the copper is deposited on the iron nail.
• D. a chemical change occurs.

Answer 1

The correct option is A the colour of the solution changes to red.

Iron nail, when dipped in a blue-coloured copper sulphate solution, reacts with it. The reaction causes a change in the colour of the solution from blue to green due to the formation of iron sulphate. A brownish deposit of copper is deposited on the iron nail. The reaction is repesented as:

Copper sulphate + Iron $\to$ Iron sulphate + Copper

The given reaction involves a chemical change since there is a formation of a new substance along with change in colour.