$A$ mixture of $4$ moles of hydrogen,$1$ mole of helium,and $1$ mole of water vapor is treated as an ideal gas mixture. What is the molar specific heat of the mixture at constant pressure?

The pressure and temperature of two different gases are $P$ and $T$,each having the same volume $V$. If they are mixed while keeping the volume and temperature constant,the pressure of the mixture will be:

$A$ mixture of $28 \ g$ of nitrogen,$4 \ g$ of hydrogen,and $8 \ g$ of helium is kept in a vessel at a temperature of $400 \ K$ and a pressure of $8.3 \times 10^5 \ Pa$. What is the density of the 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 $O_2 = 32.0 \; u$.

$A$ box contains a mixture of ${H_2}$ and $He$ gases. Which of the following statements are correct?

$A$ 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 $RT$)