Question

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

(A) Sulphur

(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 (v) A non-metal which reacts with concentrated nitric acid to form its own acid as one of the product. This can be explained with the reaction given below:

$$\begin{gathered} \mathrm{S}\left(\mathrm{s}\right)+6{\mathrm{HNO}}_3\left(\mathrm{aq}\right)\to {\mathrm{H}}_2{\mathrm{SO}}_4\left(\mathrm{aq}\right)+6{\mathrm{NO}}_2\left(\mathrm{g}\right)\uparrow +2{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right) \\ \mathrm{Sulphur}\mathrm{Nitric}\mathrm{Sulphuric}\mathrm{Nitrogen}\mathrm{Water} \\ \mathrm{Acid}\mathrm{acid}\mathrm{dioxide} \end{gathered}$$

This happens because concentrated Nitric acid ${\mathrm{HNO}}_3$behaves as a strong oxidising agent, oxidising Sulphur to its acid and reducing itself to Nitrogen dioxide ${\mathrm{NO}}_2$.

Step 2: Explanation for incorrect answers:

1. Sulphur is a non-metal but it doesn't conduct electricity. Therefore option (i) is incorrect.
2. Since it is not a compound, options (ii) and (iii) are incorrect, as both the options talk about a compound.
3. Since it is not a metal, option (iv) is incorrect.

Final answer: Correct option is (v) A non-metal which reacts with concentrated nitric acid to form its own acid as one of the product.