$A$ gaseous mixture consists of $2$ moles of oxygen and $4$ moles of argon at an absolute temperature $T$. Neglecting all vibrational modes,the total internal energy of the mixture of the gases is (in $RT$)

Two moles of an ideal gas with $\frac{C_{P}}{C_{V}}=\frac{5}{3}$ are mixed with $3$ moles of another ideal gas with $\frac{C_{P}}{C_{V}}=\frac{4}{3}$. The value of $\frac{C_{P}}{C_{V}}$ for the mixture is

One litre of oxygen at a pressure of $1 \,atm$ and two litres of nitrogen at a pressure of $0.5 \,atm$ are introduced into a vessel of volume $1 \,L$. If there is no change in temperature, the final pressure of the mixture of gas (in $atm$) is

One mole of monoatomic gas and three moles of diatomic gas are put together in a container. The molar specific heat (in $J\,K^{-1}\,mol^{-1}$) at constant volume is $(R = 8.3\,J\,K^{-1}\,mol^{-1})$.

$A$ vessel of volume $20 \ L$ contains a mixture of hydrogen and helium at a temperature of $27^{\circ} C$ and pressure $2 \ atm$. The mass of the mixture is $5 \ g$. Assuming the gases to be ideal,the ratio of the mass of hydrogen to that of helium in the given mixture will be:

$1 \, \text{mole}$ of a gas having $\gamma = \frac{7}{5}$ is mixed with $1 \, \text{mole}$ of a gas having $\gamma = \frac{4}{3}$. What will be the $\gamma$ for the mixture?