Question

When aluminium phosphide is reacted with dil. ${H_2}S{O_4}$
A. $S{O_2}$ is liberated
B. $P{H_3}$ is evolved
C. ${H_2}S$ is evolved
D. ${H_2}$ is evolved

Answer 1

Aluminium phosphide(AlP) reacts with water or acids to evolve phosphine gas. It reacts with water to form the same phosphine gas. . It is a crystalline solid which reacts with moisture to form phosphine which is a very flammable and poisonous gas.

Complete step by step answer:
We know that aluminium phosphide reacts with dilute sulfuric acid or water to evolve phosphine gas that is $P{H_3}$. The reaction taking place is given as follows

$AlP + 3{H_2}S{O_4} \to A{l_2}{(S{O_4})_3} + 2P{H_3}$

Here we can see that phosphine gas is evolved in this reaction.
Therefore in the given reaction between aluminium phosphide (AlP) and dilute sulfuric acid, phosphine gas that is $P{H_3}$ evolved.

So, the correct answer is Option B .

Additional information:
Aluminium phosphide is a highly effective low-cost insecticide rodenticide. It is also commercially available in the form of pellets. It is used to treat silicon crystals in the semiconductor industry. Phosphine gas is a metabolic poison and a lethal substance. Aluminium phosphide is a highly toxic inorganic compound used as a fumigant. It is a colorless solid which exists as a grey powder.

Note: The toxicity of aluminium phosphide is due to the liberation of phosphine gas. It is a highly toxic gas that causes free radical injury and is highly corrosive to tissues.
Also the similar reaction of aluminium phosphide with water is given down as follows

$AlP + 3{H_2}O \to Al{(OH)_3} + P{H_3}$

Accordingly, moisture in the air mixes with phosphide grains and sets off phosphine which is an active component of aluminium phosphide. Phosphine gas spontaneously ignites on coming in contact with air.