Question

The density of a gas is found to be $2.07g{L}^{-1}$ at ${30}^{\circ }C$ and $2$ atmospheric pressure. What is its density at NTP?

Answer 1

Molecular mass of gas is constant.

Applying the formula $P_1=\frac{D_1}{M}R{T}_1,P_2=\frac{D_2}{M}R{T}_2$

$T_1=303K$

At NTP, $T_2=298K$, $P=1atm$
So, $\frac{P_1}{D_1{T}_1}=\frac{P_2}{D_2{T}_2}$
$D_2$=$\frac{1\times 2.07\times 303}{2\times 298}$

=$1.149g{L}^{-1}$.