Question

The correct statement(s) related to oxoacids of phosphorous is(are)

• A. Upon heating, $H _{3} PO _{3}$ undergoes disproportionation reaction to produce $H _{3} PO _{4}$ and $PH _{3}$.
• B. While $H _{3} PO _{3}$ can act as reducing agent, $H _{3} PO _{4}$ cannot.
• C. $H _{3} PO _{3}$ is a monobasic acid.
• D. The $H$ atom of $P - H$ bond in $H _{3} PO _{3}$ is not ionizable in water.

Answer 1

Answer: (A), (B), (D)

$H_3PO_3 \xrightarrow{\Delta} H_3PO_4 + PH_3$

$P - H$ bond is responsible for it is reducing character, $H _{3} PO _{4}$ doesnot have.
$H _{3} PO _{3}$ is a dibasic acid in oxyacids of phosphors $O - H$ bond is ionisable where as $P - H$ bond is non ionizable.