Question

What is the equivalent weight of P in the following reaction?
$P_{4}+ NaOH \to NaH_{2} PO_{2} +PH_{3}$

• A. $\frac{31}{4}$
• B. $\frac{31}{3}$
• C. $\frac{31}{2}$
• D. $31 \times 4/3$

Answer 1

Answer: (D)

$P_{4} \to NaH_{2} PO_{2}$
$(P_{4})^{o} \to 4P^{+} +4e^{-}$
$\therefore Eq. wt. \left(Reductant\right) =\frac{P_{4}}{4}$
$\left(P_{4}\right)^{o}+12e \to4p^{3-} $
$\therefore Eq. wt. \left(Oxidant\right)=\frac{P_{4}}{12}$
$\therefore Eq. wt. \left(P_{4}\right)=\frac{P_{4}}{12}+\frac{P_{4}}{12}$
$=P_{4}\times\frac{16}{48}=\frac{4\times31}{3}=31\times\frac{4}{3}$