181.A gas cylinder was found unattended in a public place. The investigating team took the cylinder and collected samples from it. The density of the gas was found to be 2.380 g L–1 at 15ºC and 736 mm Hg pressure. Hence the molar mass of the gas is :- (1)83
- (2)71
- (3)32
- (4)58
182.Sulphur dioxide and oxygen were allowed to diffuse through a porpus partition. 20 dm3 of SO2 diffuses through the porous partition is 60 seconds. The volume of O2 in dm3 which diffuses under the similar condition in 30 seconds will be (atomic mass of sulphur = 32 u) :- (1)7.09
- (2)14.1
- (3)10.0
- (4)28.2
183.Which of the following equations does not represent Charles' law for a given mass of gas at constant pressure?- (1)V/T=K
- (2)logV=logK+logT
- (3)logK=logV+logT
- (4)dTd(lnV)=T1
184.The critical volume of a gas when expressed in terms of Van der Waals constants ‘a’ and ‘b’ takes the form:- (1)3a
- (2)a/27b2
- (3)8a/27Rb
- (4)3b
185.Which of the following statement (s) is/are true- (1)The pressure of a fixed amount of an ideal gas is proportional to its temperature only
- (2)Frequency of collisions increases in proportion to the square root of temperature
- (3)The value of van der Waal's constant 'a' is smaller for ammonia than for nitrogen
- (4)If a gas is expanded at constant temperature, the kinetic energy of the molecules decrease
186.Real gases approach ideal behaviour at :- (1)high temperatures and high pressure
- (2)high temperatures and low pressures
- (3)low temperatures and low pressures
- (4)critical point
187.When CO2 under high pressure is released from a fire extinguisher, particles of solid CO2 are formed, despite the low sublimation temperature (– 77ºC) of CO2 at 1.0 atm. It is- (1)the gas does work pushing back the atmosphere using KE of molecules and thus lowering the temperature
- (2)volume of the gas is decreased rapidly hence, temperature is lowered
- (3)both (a) and (b)
- (4)None of the above
188.A gas shows positive Joule-Thomson Effect below its- (1)Boyle Temperature
- (2)Critical Temperature
- (3)Inversion Temperature
- (4)Transition Temperature
189.The root mean square velocity of SO2 is equal to that of oxygen at 27°C when the temperature is- (1)327°C
- (2)127°C
- (3)227°C
- (4)600°C
190.Considering air as a 4:1 mixture of nitrogen and oxygen, the mass of air in a hall with dimensions 5 m × 5 m × 5 m at STP is approximately- (1)160 g
- (2)160 kg
- (3)16 g
- (4)1.60 kg.
191.The product of PV is plotted against P at two temperatures T1 and T2 and the 'result is shown in figure. What is correct about T1 and T2?- (1)T1 > T2
- (2)T2 > T1
- (3)T1 = T2
- (4)T1 + T2 = 1
192.The van der Waals equation for real gases is (P+a(Vn)2)(V−nb)=nRT. In the above equation, the terms a(Vn)2 and (−nb) respectively represents the corrections for- (1)intermolecular attractive forces and inelastic collision
- (2)intermolecular repulsive force and high temperatures
- (3)intermolecular attractive forces and molecular volumes
- (4)deviations in the temperature and pressure.
193.Vander Waal’s equation for a gas is stated as, P = V−nbnRT−a(Vn)2 . This equation reduces to the perfect gas equation, P = VnRT when,- (1)temperature is sufficiently high and pressure is low.
- (2)temperature is sufficiently low and pressure is high.
- (3)both temperature and pressure are very high.
- (4)both temperature and pressure are very low.
194.A liquid can exist only- (1)between triple point and critical point
- (2)at any temperature above melting point
- (3)between melting point and critical point
- (4)between boiling and melting points.
195.Real gases behave ideally at- (1)low pressure and low temperature
- (2)high pressure and low temperature
- (3)low pressure and high temperature
- (4)high pressure and high temperature
196.A gas will approach ideal behaviour at- (1)low temperature and low pressure
- (2)low temperature and high pressure
- (3)high temperature and low pressure
- (4)high temperature and high pressure
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