Question

When phosphorus reacts with caustic soda, the products are $P{H}_3$ and $Na{H}_{2}P{O}_2$. This reaction is an example of

• A. Oxidation
• B. Reduction
• C. Oxidation and reduction (Redox)
• D. Neutralization

Answer 1

Answer: (C)

Oxidation and reduction (Redox)

$P_4+3NaOH+3H_{2}O\to 3Na{H}_{2}P{O}_2+P{H}_3$
It shows oxidation and reduction (redox) properties. $P$ is in zero oxidation state. In $P{H}_3$ the oxidation state of P is $-3$ whereas in $Na{H}_{2}P{O}_2$ it is $+1$.