The density of water is $1000 \; kg \; m^{-3}$. The density of water vapour at $100 \; ^{\circ}C$ and $1 \; atm$ pressure is $0.6 \; kg \; m^{-3}$. The volume of a molecule multiplied by the total number gives what is called molecular volume. What is the average distance (in $\mathring{A}$) between atoms (interatomic distance) in water? (Radius of a water molecule $= 2 \; \mathring{A}$)

$A$ horizontal uniform glass tube of $100 \ cm$ length, sealed at both ends, contains a $10 \ cm$ mercury column in the middle. The temperature and pressure of air on either side of the mercury column are $31^{\circ} C$ and $76 \ cm$ of mercury, respectively. If the air column at one end is kept at $0^{\circ} C$ and the other end at $273^{\circ} C$, then the pressure of air which is at $0^{\circ} C$ is (in $cm$ of $Hg$):

$4.0 \, g$ of a gas occupies $22.4 \, L$ at $NTP$. The specific heat capacity of the gas at constant volume is $5.0 \, J K^{-1} mol^{-1}$. If the speed of sound in this gas at $NTP$ is $952 \, m s^{-1}$,then the heat capacity at constant pressure is .... $J K^{-1} mol^{-1}$ (Take gas constant $R = 8.3 \, J K^{-1} mol^{-1}$)

The difference between volume and pressure coefficients of an ideal gas is

An ideal gas is placed in a tank at $27^{\circ} C$. The pressure is initially $600 \ kPa$. One fourth of the gas is then released from the tank and thermal equilibrium is established. What will be the pressure if the temperature is $327^{\circ} C$ (in $kPa$)?

$A$ molecule in a gas container hits a horizontal wall with speed $200 \; m s^{-1}$ at an angle of $30^{\circ}$ with the normal,and rebounds with the same speed. Is momentum conserved in the collision? Is the collision elastic or inelastic?