1. The value of critical temperature in terms of Vander Waal’s constant a and b is

a) \[T_{C}=\frac{8a}{27Rb}\]

b) \[T_{C}=\frac{a}{2Rb}\]

c) \[T_{C}=\frac{8}{27Rb}\]

d) \[T_{C}=\frac{27a}{8Rb}\]

Explanation: The value of critical temperature in terms of Vander Waal’s constant a and b is \[T_{C}=\frac{8a}{27Rb}\]

2. In Vander Waal’s equation a and b represent \[\left(P+\frac{a}{V^{2}}\right)\left(V-b\right)=RT\]

a) Both a and b represent correction in volume

b) Both a and b represent adhesive force between molecules

c) a represents adhesive force between molecules and b correction in volume

d) a represents correction in volume and b represents adhesive force between molecules

Explanation: a represents adhesive force between molecules and b correction in volume

3. The gas in vessel is subjected to a pressure of 20 atmosphere at a temperature 27°C. The pressure of the gas in a vessel after one half of the gas is
released from the vessel and the temperature of the remainder is raised by 50°C is

a) 8.5 atm

b) 10.8 atm

c) 11.7 atm

d) 17 atm

Explanation:

4. At 0°C the density of a fixed mass of a gas divided
by pressure is x. At 100°C, the ratio will be

a) x

b) \[\frac{273}{373}x\]

c) \[\frac{373}{273}x\]

d) \[\frac{100}{273}x\]

Explanation:

5. 2 gm of \[O_{2}\] gas is taken at 27°C and pressure 76 cm. Of Hg. Then find out volume of gas (in litre)

a) 1.53

b) 2.44

c) 3.08

d) 44.2

Explanation:

6. An electron tube was sealed off during manufacture at a pressure of \[1.2 \times10^{ -7}mm\] of mercury at 27°C. Its volume is 100 cm^{3}. The number of molecules that remain in the tube is

a) \[2 \times10^{ 16}\]

b) \[3\times10^{ 15}\]

c) \[3.86 \times10^{11}\]

d) \[5 \times10^{11}\]

Explanation:

7. If the pressure of an ideal gas contained in a closed vessel is increased by 0.5%, the increase in temperature is 2K. The initial temperature of the
gas is

a) 27°C

b) 127°C

c) 300°C

d) 400°C

Explanation: If the pressure of an ideal gas contained in a closed vessel is increased by 0.5%, the increase in temperature is 2K. The initial temperature of the gas is 127°C

8. Air is filled in a bottle at atmospheric pressure and it is corked at 35°C. If the cork can come out at 3 atmospheric pressure than upto what temperature should the bottle be heated in order
to remove the cork

a) 325.5°C

b) 851°C

c) 651°C

d) None of these

Explanation:

9. A gas is collected over the water at 25°C. The total pressure of moist gas was 735 mm of mercury. If the aqueous vapour pressure at 25°C is 23.8 mm.
Then the pressure of dry gas is

a) 760 mm

b) 758.8 mm

c) 710.8 mm

d) 711.2 mm

Explanation: Total pressure (P) of gas = Actual pressure of gas

P

_{a}+ aqueous vapour pressure (P

_{V})

⇒P

_{a}=P−P

_{V}=735−23.8=711.2 mm

10. 125 ml of gas A at 0.60 atmosphere and 150 ml of gas B at 0.80 atmosphere pressure at same temperature is filled in a vessel of 1 litre volume. What will be the total pressure of mixture at the
same temperature

a) 0.140 atmosphere

b) 0.120 atmosphere

c) 0.195 atmosphere

d) 0.212 atmosphere

Explanation: