At $27°\mathrm{C}$, 500 mL of helium diffuses in 30 minutes. What is the time (in hours) taken for 1000 mL of $S{O}_2$ to diffuse under same experimental conditions?

1.  240

2.  3

3.  2

4.  4

Containers A and B have same gases. The pressure, volume and temperature of A are all twice that of B, then the ratio of number of molecules of A and B are

1.  1 : 2

2.  2 :1

3.  1 : 4

4.  3:2 

In Haber's process, 30 L of dihydrogen and 30 L of dinitrogen were taken for the reaction which yielded only 50% of the expected product. What is the composition of the gaseous mixture under afore-said conditions in the end?

1.  $20 \mathrm{L} {\mathrm{NH}}_3, 25 \mathrm{L} {\mathrm{N}}_2, 15 \mathrm{L} {\mathrm{H}}_2$

2.  $20 \mathrm{L} {\mathrm{NH}}_3, 20 \mathrm{L} {\mathrm{N}}_2, 20 \mathrm{L} {\mathrm{H}}_2$

3.  $10 \mathrm{L} {\mathrm{NH}}_3, 25 \mathrm{L} {\mathrm{N}}_2, 15 \mathrm{L} {\mathrm{H}}_2$

4.  $20 \mathrm{L} {\mathrm{NH}}_3, 10 \mathrm{L} {\mathrm{N}}_2, 30 \mathrm{L} {\mathrm{H}}_2$

If the rms velocity of a gas at 100 K is ${10}^4 \mathrm{cm} {\sec }^{-1}$, what is the temperature $\left(\mathrm{in} °\mathrm{C}\right)$ at which the rms velocity will be $3\times {10}^4 \mathrm{cm} {\sec }^{-1}$?

1.  900

2.  627

3.  327

4.  1217 

A solution has a 1 : 4 mole ratio of pentane to hexane. The vapour pressures of the hydrocarbons at 20$°$C are 400 mm Hg for pentane and 120 mm hg for hexane. The mole fraction of pentane in the vapour phase would be

1. 0.200

2. 0.549

3. 0.454

4. 0.478

The temperature at which rate of diffusion of $N_2$ would be 1.625 times the rate of diffusion of $S{O}_2 at 50°\mathrm{C\; is\; : }$

1. 110 K

2. 173 K

3. 373 K

4. 273 K

If Vrms of $H_2 at 300K is 1.9\times {10}^3$ m/s. What is the value of Vrms of $O_2$ at 1200K?

1. 1.9 $\times {10}^3$

2. 3.8$\times {10}^3$ m/s

3. 0.475$\times {10}^3$ m/s

4. 0.95$\times {10}^3$ m/s

The average velocity of ideal gas molecules at 27$°C$ is 0.3 m/sec. The average velocity at 927$°C$ will be 

1. 0.6 m/sec

2. 0.3 m/sec

3. 0.9 m/sec

4. 3.0 m/sec

equal masses of methane and hydrogen are mixed in an empty container at $25°C.$ The fraction of the total pressure exerted by hydrogen is

1. 1/2

2. 8/9

3. 1/9

4. 16/17

A 2.24 L cylinder of oxygen at STP is found to develop a leakage. When the leakage was plugged, the pressure dropped to 570 mm of Hg. The number of moles of gas that escaped will be:

1. 0.050

2. 0.025

3. 0.075

4. 0.01