$A$ gas mixture consists of equal masses of Helium and Oxygen. What is the ratio of $C_P$ to $C_V$ for the mixture?

If $\alpha$ moles of a monoatomic gas are mixed with $\beta$ moles of a polyatomic gas and the mixture behaves like a diatomic gas,then [neglect the vibrational mode of freedom]:

$A$ gas mixture consists of $2$ moles of oxygen and $4$ moles of neon at temperature $T$. Neglecting all vibrational modes,the total internal energy of the system will be $...........\,RT$.

One mole of an ideal monoatomic gas $(\gamma = 5/3)$ is mixed with one mole of a diatomic gas $(\gamma = 7/5).$ What is $\gamma$ for the mixture? $\gamma$ denotes the ratio of specific heat at constant pressure to that at constant volume.

$A$ container has two chambers of volumes $V_1=2 \ L$ and $V_2=3 \ L$ separated by a partition made of a thermal insulator. The chambers contain $n_1=5$ and $n_2=4$ moles of an ideal gas at pressures $p_1=1 \ atm$ and $p_2=2 \ atm$,respectively. When the partition is removed,the mixture attains an equilibrium pressure of: (in $atm$)

Find $\gamma$ for the mixture of $11 \, g$ of $CO_{2}$ and $14 \, g$ of $N_{2}$.