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

$A$ container of fixed volume has a mixture of one mole of hydrogen and one mole of helium in equilibrium at temperature $T$. Assuming the gases are ideal,the correct statement$(s)$ is(are):
$(A)$ The average energy per mole of the gas mixture is $2RT$.
$(B)$ The ratio of speed of sound in the gas mixture to that in helium gas is $\sqrt{6/5}$.
$(C)$ The ratio of the rms speed of helium atoms to that of hydrogen molecules is $1/2$.
$(D)$ The ratio of the rms speed of helium atoms to that of hydrogen molecules is $1/\sqrt{2}$.

Four moles of hydrogen,two moles of helium,and one mole of water vapour form an ideal gas mixture. What is the molar specific heat at constant pressure of the mixture?

$1 \, g$ of $H_2$ at $27 \, ^oC$ is mixed with $16 \, g$ of $O_2$ at $37 \, ^oC$. The temperature of the mixture is about ....... $^oC$.

Two ideal gases $A$ and $B$ having the same temperature $T$,same pressure $P$,and same volume $V$,are mixed together. If the temperature of the mixture is kept constant and the volume occupied by the mixture is reduced to $\frac{V}{2}$,then the pressure of the mixture will become:

When $16 \ gm$ of $O_2$ at $37^{\circ}C$ is added to $22 \ gm$ of $CO_2$ at $27^{\circ}C$,what is the final temperature in $^{\circ}C$?