Question

When Sulphur is boiled with ${\mathrm{Na}}_2{\mathrm{SO}}_3$ solution, the Compound formed is

• A. Sodium Sulphide
• B. Sodium Sulphate
• C. Sodium Thiosulphate.
• D. Sodium Persulphate.

Answer 1

The correct option is C

Sodium Thiosulphate.

Explanation for correct option:

(C) Sodium Thiosulphate

• When Sulphur reacts with sodium sulphite gives sodium thiosulphate
• The water-soluble sodium thiosulphate is formed also called hypo.
• It will be in yellow colour.

$$\begin{gathered} {\mathrm{Na}}_2{\mathrm{SO}}_3\left(\mathrm{aq}\right)+\mathrm{S}\left(\mathrm{s}\right)\to {\mathrm{Na}}_2{\mathrm{S}}_2{\mathrm{O}}_3\left(\mathrm{aq}\right) \\ \mathrm{Sodium}\mathrm{sulphite}\mathrm{Sodium}\mathrm{thiosulphate} \end{gathered}$$

Explanation for incorrect answer:

(A) Sodium Sulphite

• When sulphur dioxide and sodium hydroxide react then only sodium sulphite forms. So, this is an incorrect option.

(B) Sodium Sulphate

• When Sodium Carbonate and diluted Sulphuric acid reacts then only Sodium Sulphiate forms. So, this is an incorrect option.

(D) Sodium Persulphate

• When Sodium hydroxide reacts with Ammonium persulphate then only sodium persulphate is formed. So, this is an incorrect option.

Therefore, the correct option is (C) Sodium Thiosulphate.