Question

The density of a gas at $27C$ and $1atm$ pressure is $\rho$. Pressure remaining constant, the temperature at which its density is $0.5\rho$ is:

• A. $200K$
• B. $400K$
• C. $600K$
• D. $800K$

Answer 1

Answer: (C)

$600K$

$\rho =\frac{PM}{RT}$

For same substance under the same pressure,

$\rho \propto \frac{1}{T}$

Hence, to reduce the density to half its initial value, the temperature must be doubled

$\Rightarrow T_f=2\times 27+273=600K$