The reaction of white phosphorus ${\text{P}}_4$ with concentrated $\text{NaOH}$ solution produces which of the following products?

Solution

1. The reaction is ${\text{P}}_4+3\text{NaOH}+3{\text{H}}_2\text{O}\to {\text{PH}}_3+3{\text{NaH}}_2{\text{PO}}_2$.
2. In this reaction, phosphorus is simultaneously oxidized and reduced.
3. The products are phosphine gas and sodium hypophosphite.
4. Hence the answer is (A).