Question

If the weight of $5.6$lit of a gas at NTP is $11g$, the gas may be_______.

(Atomic wt. of $P=31,N=14,O=16$ and $Cl=35.5$)

• A. phosphine
• B. phosgene
• C. nitric oxide
• D. nitrous oxide

Answer 1

The correct option is D nitrous oxide

At NTP, T=293.15 K and P = 1 atm

$PV=nRT⟹\frac{11g}{M}=\frac{1atm\times 5.6lit}{(0.0821lit-atm{mol}^{-1}{K}^{-1})\times \left(293.15K\right)}⟹M=47$

Molecular weight of nitrous oxide is 44g/mol.

So, the gas maybe nitrous oxide as value is very close to the molecular weight of nitrous oxide.