One mole of ideal monoatomic gas $\left(\mathrm{\gamma }=5/3\right)$ is mixed with one mole of diatomic gas $\left(\mathrm{\gamma }=7/5\right)$. What is $\mathrm{\gamma }$ for the mixture? $\mathrm{\gamma }$ denotes the ratio of specific heat at constant pressure, to that at constant volume

1.  3/2                             

2.  23/15

3.  35/23                         

4.  4/3

A gaseous mixture contains equal number of hydrogen and nitrogen molecules. Specific heat measurements on this mixture at temperatures below 100 K would indicate that the value of $\mathrm{\gamma }$ (ratio of specific heats) for this mixture is

1.  3/2                           

2.  4/3

3.  5/3                           

4.  7/5

One mole of monoatomic gas and three moles of diatomic gas are put together in a container. The molar specific heat $\left(\mathrm{in} \mathrm{J} {\mathrm{K}}^{-1} {\mathrm{mol}}^{-1}\right)$ at constant volume is $\left(\mathrm{R}=8.3 \mathrm{J} {\mathrm{K}}^{-1} {\mathrm{mol}}^{-1}\right)$

1.  18.7                           

2.  18.9

3.  19.2                           

4.  None of the above

The number of translational degrees of freedom for a diatomic gas is

1.  2                           

2.  3

3.  5                           

4.  6

A gaseous mixture consists of 16g of helium and 16g of oxygen. The ratio $\frac{{\mathrm{C}}_{\mathrm{P}}}{{\mathrm{C}}_{\mathrm{V}}}$ of the mixture is

1.  1.4                       

2.  1.54

3.  1.59                     

4.  1.62

The pressure exerted by the gas on the walls of the container because

1. It loses kinetic energy

2. It sticks with the walls

3. On collision with the walls there is a change in momentum

4. It is accelerated towards the walls

Gas at a pressure ${\mathrm{P}}_0$ is contained in a vessel. If the masses of all the molecules are halved and their speeds are doubled, the resulting pressure P will be equal to

1.  $4{\mathrm{P}}_0$                                 

2.  $2{\mathrm{P}}_0$

3.  ${\mathrm{P}}_0$                                   

4.  $\frac{{\mathrm{P}}_0}{2}$

A box contains n molecules of a gas. How will the pressure of the gas be effected, if the number of molecules is made 2n?

1. Pressure will decrease

2. Pressure will remain unchanged

3. Pressure will be doubled

4. Pressure will become three times

Consider a gas with density $\mathrm{\rho }$ and $\overline{\mathrm{c}}$ as the root mean square velocity of its molecules contained in a volume. If the system moves as whole with velocity v, then the pressure exerted by the gas is

1.  $\frac{1}{3}\mathrm{\rho }{\overline{\mathrm{c}}}^{ 2}$                                   

2.  $\frac{1}{3}\mathrm{\rho }{\left(\mathrm{c}+\mathrm{v}\right)}^2$

3.  $\frac{1}{3}\mathrm{\rho }{\left(\overline{\mathrm{c}}-\mathrm{v}\right)}^2$                         

4.  $\frac{1}{3}\mathrm{\rho }{\left({\mathrm{c}}^{-2}-\mathrm{v}\right)}^2$

In kinetic theory of gases, a molecule of mass m of an ideal gas collides with a wall of vessel with velocity V. The change in the linear momentum of the molecule is

1.  2mV                           

2.  mV

3.  – mV                           

4.  Zero