The pressure exerted by a mixture of $3.2 \ g$ of methane $(CH_4)$ and $4.4 \ g$ of $CO_2$ contained in a $9 \ dm^3$ flask at $27^{\circ}C$ is: (in $atm$)

At $300 \ K$ and $760 \ torr$ pressure,the density of a mixture of $He$ and $O_2$ gases is $0.543 \ g \ L^{-1}$. The mass percent of oxygen is approximately $(R = 0.0821 \ L \ atm \ K^{-1} \ mol^{-1})$

Assertion : Wet air is heavier than dry air.
Reason : The density of dry air is more than density of water.

Consider the following statements:
Statement-$I$: If thermal energy is stronger than intermolecular forces,the substance prefers to be in a gaseous state.
Statement-$II$: At constant temperature,the density of an ideal gas is proportional to its pressure.
The correct answer is:

At $100\,^\circ\text{C}$ and $1 \, \text{atm}$ pressure,if the density of liquid water is $1.0 \, \text{g cm}^{-3}$ and the density of water vapor is $0.0006 \, \text{g cm}^{-3}$,then the volume occupied by water molecules in $1 \, \text{L}$ of steam is ............. $\text{cm}^3$.

What is the temperature at which the kinetic energy of $0.3 \text{ moles}$ of helium is equal to the kinetic energy of $0.4 \text{ moles}$ of argon at $400 \text{ K}$ (in $\text{ K}$)?