Question

In the given reaction:

$4H_{3}P{O}_3⟶3H_{3}P{O}_4+P{H}_3$,

Equivalent weight of $H_{3}P{O}_3$ is :

• A. 41
• B. 54.67
• C. 72.89
• D. 82

Answer 1

The correct option is B 54.67

$4H_{3}P{O}_3⟶3H_{3}P{O}_4+P{H}_3$
+3 +5 -3

Equivalent weights $E_1=\frac{mol.wt.}{2}{E}_2=\frac{mol.wt.}{6}$
$\therefore$ Eq. wt. of $H_{3}P{O}_3$ in disproportionation reaction:

$=E_1+E_2$

$=\frac{2}{3}mol.wt.=\frac{2}{3}\times 82$

$=54.67$

Hence, option B is correct.