Question

What is the product formed when phosphorus pentoxide is boiled with hot water?

• A. $H_{3}P{O}_4$
• B. $HP{O}_3$
• C. $H_{3}P{O}_3$
• D. $H_4{P}_2{O}_6$

Answer 1

Answer: (A)

$H_{3}P{O}_4$

Phosphoric acid $\left(H_{3}P{O}_4\right)$ is the product formed when phosphorus pentoxide is boiled with hot water.

Burning P in air produces$P_2{O}_5$ which dissolves in water to form $H_{3}P{O}_4$ - ortho phosphoric acid which is a strong acid.
$P_2{O}_5+3H_{2}O\to 2H_{3}P{O}_4$