Question

Anhydrous $AlC{l}_3$ fumes in air. What is the reason for it?

• A. It is hygroscopic in nature
• B. It gives out chlorine when exposed to air.
• C. It is hydrolysed in moist air giving out fumes of $HCl$.
• D. It loses water when exposed to moist air.

Answer 1

The correct option is C It is hydrolysed in moist air giving out fumes of $HCl$.

White fumes are due to the presence of $HCl$ gas.

Anhydrous aluminium chloride is hydrolysed partially with the moisture in the atmosphere to give $HCl$ gas.

This HCl combines with the moisture in the air and appears white in colour.

$Al{Cl}_3+3H_{2}O⟶Al{\left(OH\right)}_3+3HCl\text{(white fumes)}$

Hence, the correct answer is option $\text{C}$.