Consider the following reaction : A + alkali $\rightarrow$ B (Major Product) If B is an oxoacid of phosphorus with no $\mathrm{P}-\mathrm{H}$ bond, then A is :

(C) $\mathrm{P}_{2} \mathrm{O}_{3}$

(D) $\mathrm{H}_{3} \mathrm{PO}_{3}$

JEE Main · 2022 · 26 Jun 2022 · Shift 1 · p-Block Elements

Consider the following reaction :

A + alkali

\to

B (Major Product)
If B is an oxoacid of phosphorus with no

P - H

bond, then A is :

(A)White $P_{4}$
(B)Red $P_{4}$ ✓ Correct
(C) $P_{2} O_{3}$
(D) $H_{3} PO_{3}$

Answer: (B)

Solution

Red phosphorus reacts with alkali to form hypophosphoric acid (

H_{4} P_{2} O_{6}

), which is an oxoacid of phosphorus with no P-H bonds.

Red

P_{4}

+ Alkali →

H_{4} P_{2} O_{6}

White phosphorus with alkali gives phosphine (

PH_{3}

) and hypophosphite, which contains P-H bonds.

JEE Main · 2022 · 26 Jun 2022 · Shift 1 · Single correct option

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