Oxygen gas is filled in a container of volume $20 \, L$ at a pressure of $2.5 \times 10^5 \, N \, m^{-2}$. Find the mass of the oxygen gas in the container. The temperature of the oxygen in the container is $27 \, ^\circ C$,the molar mass of oxygen is $32 \, g \, mol^{-1}$,and $R = 8.31 \, J \, mol^{-1} K^{-1}$.

Two containers $C_{1}$ and $C_{2}$ of volumes $V$ and $4V$ respectively,hold the same ideal gas and are connected by a thin horizontal tube of negligible volume with a valve which is initially closed. The initial pressures of the gas in $C_{1}$ and $C_{2}$ are $p$ and $5p$,respectively. Heat baths are employed to maintain the temperatures in the containers at $300 \, K$ and $400 \, K$,respectively. The valve is now opened. Select the correct statement.

$A$ monoatomic ideal gas of two moles is taken through a cyclic process starting from $1$ as shown. Given $\frac{V_2}{V_1} = 2$ and $\frac{V_4}{V_1} = 4$. The temperature at state $1$ is $T_1 = 27\,^oC$. Find the temperature at state $2$,i.e.,$T_2$ in $K$.

$A$ gas of certain mass filled in a closed cylinder at a pressure of $3.23 \ kPa$ has a temperature of $50^{\circ} C$. The gas is now heated until its absolute temperature is doubled. The modified pressure is . . . . . . $Pa$.

Dry air at sea level contains $75.5\%\, N_2$ by mass. If the total atmospheric pressure is $1 \,atm$,the partial pressure of nitrogen is approximately $... \,atm$.

The $PV$ versus $T$ graph for equal masses of $H_2$,$He$,and $O_2$ is shown in the figure. Choose the correct alternative.