The density of a gas is 2g/L at 1 atm and 27ºC. The density of the same gas at 2 atm and 127ºC is

${\mathrm{d}}_1=2\mathrm{g}/\mathrm{L} {\mathrm{P}}_2=2\mathrm{atm}$

${\mathrm{p}}_1=1 \mathrm{atm} {\mathrm{T}}_2=400\mathrm{K}$

${\mathrm{T}}_1=300\mathrm{K} {\mathrm{d}}_2=?$

$\frac{{\mathrm{d}}_1}{{\mathrm{d}}_2}=\frac{P_1{T}_2}{P_2{T}_1}$

$\frac{2}{{\mathrm{d}}_2}=\frac{1\times 400}{2\times 300}$

${\mathrm{d}}_2=3\mathrm{g}/\mathrm{L}$