Question

4. Match each substance A to E listed below with the appropriate description in parts (i) to (v):

(D) Copper (II) sulphate

(i) A non-metal which is a good conductor of electricity

(ii)A covalent compound which behaves like an ionic compound in aqueous solution

(iii) A compound which is insoluble in cold water but soluble in excess of ammonia solution.

(iv) A pink metal which is deposited at the cathode during the electrolysis of the solution of this Salt.

(v) A non-metal which reacts with concentrated nitric acid to form its own acid as one of the product.

Answer 1

Step 1:Explanation for correct option:

The correct option is (iv) A pink metal which is deposited at the cathode during the electrolysis of the solution of this salt. During the electrolysis of Copper sulphate ${\mathrm{CuSO}}_4$ solution, copper ions get reduced to copper metal at the cathode. This results in the deposition of a pink-coloured metal copper at the cathode. The following chemical transformation is seen:

$$\begin{gathered} {\mathrm{Cu}}^{+2}+{\mathrm{e}}^{-}\stackrel{\mathrm{Electrolysis}}{\to }\mathrm{Cu}\downarrow \\ \mathrm{Copper}\mathrm{ion}\mathrm{copper}\mathrm{metal}\left(\mathrm{pink}\right) \end{gathered}$$

Step 2: Explanation for incorrect answers:

1. Since it is not non-metal, options (i) and (v) are incorrect.
2. Since it is soluble in water and breaks into ions, option (iii) is incorrect.
3. Since it is not a covalent compound, option (ii) is also incorrect.

Final answer: The correct option is (iv) A pink metal which is deposited at the cathode during the electrolysis of the solution of this salt.