Chemistry - Complete P-block Question with Solution | TestHub

Let's analyze each reaction to determine if it produces PH₃ gas.

A. Reaction of phosphonium iodide with a strong base:

$${\mathrm{PH}}_4\mathrm{I}+\mathrm{KOH}⟶{\mathrm{PH}}_3+\mathrm{KI}+{\mathrm{H}}_2\mathrm{O}$$

This reaction produces PH₃ gas.

B. Hydrolysis of phosphorus trichloride:

$${\mathrm{PCl}}_3+3{\mathrm{H}}_2\mathrm{O}⟶{\mathrm{H}}_3{\mathrm{PO}}_3+3\mathrm{HCl}$$

This reaction produces phosphorous acid (${\mathrm{H}}_3{\mathrm{PO}}_3$) and hydrochloric acid, NOT PH₃ gas.

C. Reaction of white phosphorus with a strong base (disproportionation reaction):

$${\mathrm{P}}_4+3\mathrm{NaOH}+3{\mathrm{H}}_2\mathrm{O}⟶{\mathrm{PH}}_3+3{\mathrm{NaH}}_2{\mathrm{PO}}_2$$

This reaction produces PH₃ gas.

D. Hydrolysis of aluminum phosphide:

$$\mathrm{AlP}+3\mathrm{HCl}⟶{\mathrm{PH}}_3+{\mathrm{AlCl}}_3$$

This reaction produces PH₃ gas.

Therefore, the reaction that cannot give PH₃ gas is B.

The final answer is $\boxed{B}$