Two different gases have pressure $P$ and temperature $T$. Their volume is $V$. If these two gases are mixed while keeping the volume and temperature the same,the pressure of the mixture will be...........

$A$ gaseous mixture consists of $16\,g$ of helium and $16\,g$ of oxygen. The ratio $\frac{C_P}{C_V}$ of the mixture is

One gram of $H_2$ at $27\,^{\circ}C$ is mixed with $16\,g$ of $O_2$ at $37\,^{\circ}C$. The temperature of the mixture is about ....... $^{\circ}C$.

If $22 \, g$ of $CO_2$ gas at $27 \, ^\circ C$ and $16 \, g$ of $O_2$ gas at $37 \, ^\circ C$ are mixed,the final temperature of the mixture will be ...... $^\circ C$.

$A$ gas mixture consists of $2$ moles of $O_2$ and $4$ moles of $Ar$ at temperature $T$. Neglecting all vibrational modes,the total internal energy of the system is (in $RT$)

Two rigid boxes placed on a table contain different ideal gases. Box $A$ contains $1 \text{ mole}$ of nitrogen at temperature $T_0$. Box $B$ contains $1 \text{ mole}$ of helium at temperature $(7/3) T_0$. Both boxes are brought into thermal contact,and heat flows until they reach a common final temperature $T_f$. (Neglect the heat capacity of the boxes). Express the final temperature $T_f$ in terms of $T_0$.