Question

Equivalent weight of $H_{3}P{O}_2$ when it disproportionates into $P{H}_3$ and $H_{3}P{O}_3$ is (mol. wt. of $H_{3}P{O}_2=M$)

• A. $M$
• B. $\frac{3M}{4}$
• C. $\frac{M}{2}$
• D. $\frac{M}{4}$

Answer 1

Answer: (B)

$H_{2}P{O}_2\to P{H}_3$
$P^{+}+4e^{-}\to P^{3-}$
$\therefore Eq.wt.\left(H_{3}P{O}_2\right)=M/4$ $H_{3}P{O}_2\to {\text{H}}_{3}P{O}_3$
$P^{+}\to P^{3+}+2e^{-}$
$\therefore Eq,w.t.\left(H_{3}P{O}_2=M2\right)Hence,$
$Eq.wt.\left(H_{3}P{O}_2\right)=\frac{M}{4}+\frac{M}{2}=\frac{3}{4}M$