$A$ vessel contains $3$ moles of $He$,$1$ mole of $Ar$,$5$ moles of $N_2$,and $3$ moles of $H_2$. If the vibrational modes are ignored,the total internal energy of the system of gases is (in $RT$)

If $7 \, g$ of $N_{2}$ is mixed with $20 \, g$ of $Ar$,the $C_{p} / C_{v}$ ratio of the mixture will be:

Two thermally insulated vessels $1$ and $2$ are filled with air at temperatures $T_1, T_2$,pressures $P_1, P_2$,and volumes $V_1, V_2$ respectively. If the valve connecting them is opened,what is the temperature of the equilibrium mixture?

$A$ vessel contains two non-reactive gases: neon (monatomic) and oxygen (diatomic). The ratio of their partial pressures is $3:2$. Estimate the ratio of
$(i)$ number of molecules and
$(ii)$ mass density of neon and oxygen in the vessel.
Atomic mass of $Ne = 20.2 \; u$,molecular mass of $O_2 = 32.0 \; u$.

Five moles of helium are mixed with two moles of hydrogen to form a mixture. Take molar mass of helium $M_1=4 \ g$ and that of hydrogen $M_2=2 \ g$. The equivalent degree of freedom $f$ of the mixture is:

The volume $V$ of an enclosure contains a mixture of three gases: $16 \, g$ of oxygen,$28 \, g$ of nitrogen,and $44 \, g$ of carbon dioxide at absolute temperature $T$. Consider $R$ as the universal gas constant. The pressure of the mixture of gases is: