Question

Identify the. compound in which phosphorus exists in the oxidation state of $+1$.

• A. Phosphonic acid $(H_{3}P{O}_3)$
• B. Phosphinic acid $(H_{3}P{O}_2)$
• C. Pyrophosphorus acid $(H_4{P}_2{O}_5)$
• D. Orthophosphoric acid $(H_{3}P{O}_4)$

Answer 1

Answer: (B)

The oxidation state of $P$ atom in phosphonic acid $H_{3}P{O}_3$ is:
$3+x-6=0$
$x=+3$
The oxidation state of $P$ atom in phosphinic acid $H_{3}P{O}_2$ is:
$3+x-4=0$
$x=+1$
The oxidation state of $P$ atom in pyrophosphorus acid $H_4{P}_2{O}_5$ is:
$4+x-10=0$
$x=+3$
The oxidation state of $P$ atom in orthophosphoric acid $H_{3}P{O}_4$ is:
$3+x-8=0$
$x=+5$