Question

The percentage of $P_2{O}_5$ in diammonium hydrogen phosphate is;

• A. 77.58
• B. 46.96
• C. 53.78
• D. 23.48

Answer 1

Answer: (C)

53.78

2 (NH₄)₂HPO₄ ⇒ P₂O₅

2 moles of diammonium hydrogen phosphate yield 1 mole of P₂O₅

The molar mass of (NH₄)₂HPO₄ = 36 + 1 + 31 + 44

Molar mass of P₂O₅ = 62 + 80 = 142g

So, percentage of P₂O₅ is

= [$\frac{142}{2\times 132}$] x100

= 53.78%

Therefore percentage of P₂O₅ is 53.78%.