At what temperature in the Celsius scale,$V$ (volume) of a certain mass of gas at $27\,^oC$ will be doubled keeping the pressure constant?

The value of the universal gas constant $R$ is the same for all gases. What is its physical significance?

For an ideal gas,the value of ${\left( {\frac{{dU}}{{dV}}} \right)_T}$ is ...... .

$A$ student forgot to add the reaction mixture to the round bottomed flask at $27^{\circ} C$ but instead he/she placed the flask on the flame. After a lapse of time,he realized his mistake,and using a pyrometer he found the temperature of the flask was $477^{\circ} C$. What fraction of air would have been expelled out?

If $20 \ cm^3$ of gas at $1 \ atm$ is expanded to $50 \ cm^3$ at constant $T$,what is the final pressure?

At $127 \, ^oC$ temperature,the volume of a gas is $3 \, L$. If the volume of the gas becomes half at constant pressure,calculate the final temperature in Kelvin. (in $, K$)