Question

The density of a gas at ${27}^{\circ }\text{C}$ and 1 atm is $d$. If the pressure is constant, at which of the following temperatures will its density become $0.75d$?

• A. ${20}^{\circ }\text{C}$
• B. ${30}^{\circ }\text{C}$
• C. $400\text{K}$
• D. $300\text{K}$

Answer 1

The correct option is C $400\text{K}$

$P=\frac{dRT}{M}$
At constant pressure,
$dT=\text{constant}\Rightarrow d_1{T}_1=d_2{T}_2$
$d\times 300=0.75d\times T_2$
$T_2=100\times 4\Rightarrow 400\text{K}$