Two flasks of equal volume are connected by a narrow tube (of negligible volume) at 27ºC and contain 0.70 mole of ${\mathrm{H}}_2$ at 0.5 atm. One of the flasks is then immersed in a hot bath, kept at 127 ºC, while the other remains at 27 ºC. The final pressure is -

1. 5.714 atm                   

2. 0.5714 atm

3. 2.5214 atm                 

4. 5.5114 atm

Oxygen is present in 1-litre flask at a pressure of $7.6\times$ ${10}^{–10}$ mmHg.The number of oxygen molecules in the flask at $0$ $º\mathrm{C}$ is -

1. $2.686$ $\times$ ${10}^{10}$                            

2. $26.86$ $\times$ ${10}^{10}$

3. $0.626$ $\times$ ${10}^{12}$                            

4. $4.123$ $\times$ ${10}^8$

Choose the correct statement for viscosity ($\mathrm{\eta }$) variation with T and P for an ideal gas-

1. $\mathrm{\eta }$ of a gas increases with increase in temperature (T), but it is independent of pressure

2. $\mathrm{\eta }$ of a gas decreases with increase in T and increases with increase in P

3. $\mathrm{\eta }$ of a gas is independent of temperature and pressure

4. $\mathrm{\eta }$ of a gas increases with increase in both T and P

Flask X is filled with 20 g of ${\mathrm{CH}}_4$ gas at 100 °C and another identical flask Y with 40 g ${\mathrm{O}}_2$ gas at the same temperature. The correct statement among the following is –

1. The pressure of the gases in the two flasks is identical

2. The pressure of ${\mathrm{CH}}_4$ in flask X is higher than that of ${\mathrm{O}}_2$ in flask Y

3. The pressure of ${\mathrm{CH}}_4$ in flask X is lower than that of ${\mathrm{O}}_2$ in flask Y

4. The pressure of ${\mathrm{CH}}_4$ in flask X is half that of ${\mathrm{O}}_2$ in flask Y

The pressure-volume plot for an ideal gas at a given temperature has the form of a -

1. Straight line                               

2. Exponential curve

3. Rectangular hyperbola                 

4. U-shaped curve

A vessel of volume $0.02$ ${\mathrm{m}}^3$ contains a mixture of hydrogen and helium at 20°C and 2 atm pressure. The mass of the mixture is 5 g. The ratio of the mass of hydrogen to that of helium in the mixture, is -

1. 1:2                           

2. 1:3

3. 2:3                           

4. 3:2

For a real gas, PV is a constant over a small range of pressures  at-

1. Boyle’s temperature                             

2. Critical temperature

3. Inversion temperature                           

4. Ordinary temperature

A certain hydrate has the formula ${\mathrm{MgSO}}_4.$ ${\mathrm{xH}}_2\mathrm{O}$. A quantity of 54.2 g of the compound is heated in an oven to drive off the water. If the water vapour generated exerts a pressure of 24.8 atm in a 2.0 L container at 120$°\mathrm{C}$, the value of x is-

1.  2

2.  5

3.  6

4.  7

The correct order of temperature of a real gas is-

I. Boyle's temperature

II. Critical temperature

III. Inversion temperature

1.  III > I > II

2.  I > II > III

3.  II > I > III

4.  I > III > II

A mixture of He and Ar weighting 5.0 g occupies a volume of $10$ ${\mathrm{dm}}^3$ $\mathrm{at}$ $27°\mathrm{C}$ and 1 atm pressure. The composition of the mixture is respectively -

1. 70%, 30%

2. 25%,75%

3. 75%,25%

4. 40%,60%