Question

For $H_{3}P{O}_{3}and{H}_{3}P{O}_4,$ the correct choice is

• A. $H_{3}P{O}_3$ is dibasic and reducing
• B. $H_{3}P{O}_3$is dibasic and non-reducing
• C. $H_{3}P{O}_4$is tribasic and reducing
• D. $H_{3}P{O}_3$is tribasic and non-reducing

Answer 1

Answer: (A)

$H_{3}P{O}_3$ is a dibasic acid as it has $2$ number of replaceable $OH$ groups(Dibasic) attached to phosphorous. The oxyacids of phosphorous are reducing agents. $H_{3}P{O}_3$ is a good reducing agent than $H_{3}P{O}_4$. The reducing nature of these acids is based on the no of hydrogen atoms bonded to the central metal atom. As more number of $H$ attached to phosphorous more is its reducing nature. In the case of $H_{3}P{O}_3$, there is one $P-H$ bond which is responsible for it's reducing character whereas there is no such bonding in case of $H_{3}P{O}_4$.