Question

The compound obtained by the reaction of sodium chloride and sulphuric acid at a temperature
below $200°C$ is:

• A. Sodium sulphate
• B. Sodium bisulphate
• C. Sodium sulphonate
• D. Sodium sulphide

Answer 1

The correct option is B

Sodium bisulphate

Explanation for correct option:

(B) Sodium bisulphate:

The compound formed by reaction of sulphuric acid and sodium chloride:

• The reaction of sodium chloride $\left(NaCl\right)$ and sulphuric acid $\left(H_{2}S{O}_4\right)$ gives a double displacement reaction.
• When they are heated together at room temperature or at a temperature less than $200°$ given sodium bisulphate and hydrochloric acid.
• The hydrochloric acid is given out as gas.
• But when they are heated together at a temperature greater than $200°$ gives sodium sulphate and hydrochloric acid.
• Therefore, the option (B) sodium bisulphate is correct.

$NaCl+H_{2}S{O}_4\to NaHS{O}_4\left(s\right)+HCl\left(g\right)\downarrow$

Explanation for incorrect option:

(A) Sodium sulphate:

• When the compounds are heated below $200°$ they form sodium bisulphate instead of sodium sulphate.

(C) Sodium sulphonate:

• Sodium sulphonate is not formed when sodium chloride and sulphuric acid are heated below $200°$.

(D) Sodium sulphide:

• Sodium sulphide is not formed when sulphuric acid and sodium chloride are heated.