Question

The density of a gas is 16 at NTP. At what temperature its density will be 14 if the pressure remains constant?

• A. ${50}^{o}C$
• B. ${39}^{o}C$
• C. ${57}^{o}C$
• D. ${43}^{o}C$

Answer 1

The correct option is B ${39}^{o}C$

Since pressure is constant, we can use Charle's law to obtain the temperature

Hence, $\frac{V_1}{T_1}=\frac{V_2}{T_2}$

Since molecular mass is constant,

${\rho }_1{T}_1={\rho }_2{T}_2$

$\Rightarrow 16\times 273=14\times T_2$

$\Rightarrow T_2=312K={39}^{o}C$