Question

In the following unbalanced redox reaction,
$C{u}_{3}P+C{r}_2{O}_7^{2-}\to C{u}^{2+}+H_{3}P{O}_4+C{r}^{3+}$
Equivalent weight of $H_{3}P{O}_4$ is

• A. $\frac{M}{3}$
• B. $\frac{M}{6}$
• C. $\frac{M}{7}$
• D. $\frac{M}{8}$

Answer 1

Answer: (D)

Change in oxidation number = $8$ units of phosphorus
$\therefore$ Equivalent weight of $H_{3}P{O}_4=\frac{M}{8}$