A flask containing air (open to the atmosphere)
is heated from 300 K to 500 K. The percentage
of air escaped to the atmosphere is
1. 16.6
2. 40
3. 60
4. 20
The rate of diffusion of two gases A and B is in
the ratio of 1 : 4 and the B and C in the ratio
1 : 3 the rate of diffusion of C with respect to A
is
1. 1/12
2. 12
3. 3
4. 4
A sample of air contains only N2, O2 and H2O. It
is saturated with water vapours and the total
pressure of 640 torr. The vapour pressure of
water is 40 torr and the molar ratio of N2: O2
is 3 : 1. The partial pressure of N2
in the sample in
1. 480 torr
2. 600 torr
3. 525 torr
4. 450 torr
The temperature at which the r.m.s. velocity of
carbon dioxide becomes the same as that of
nitrogen at 21°C is
1. 462°C
2. 273K
3. 189°C
4. 546K
Which set of conditions represents easiest way
of liquify a gas?
1. Low temperature and high pressure
2. High temperature and low pressure
3. Low temperature and low pressure
4. High temperature and high pressure
If excluded volume is taken zero,
compressibility factor Z is
1.
2.
3.
4.
Root means square velocity of gas molecule is
300 m/sec. The r.m.s. velocity of molecules of
gas with twice the molecular weight and half the
absolute temperature is
1. 300 m/s
2. 600 m/s
3. 75 m/s
4. 150 m/s
Boyle’s law may be expressed as
1.
2.
3.
4. None
A vessel has N2 gas and water vapours at a total
pressure of 1 atm. The partial pressure of water
vapours is 0.3 atm. The contents of this vessel
are transferred to another vessel having one
third of the capacity of original volume,
completely at the same temperature, the total
pressure of this system in the new vessel is
1. 3.0 atm
2. 1 atm
3. 3.33 atm
4. 2.4 atm
If for two gases of molecular weights MA and MB at temperature TA and TB, TAMB = TBMA, then which property has the same magnitude for both the gases?
1. Density
2. Pressure
3. KE per mol
4. Vrms
Which of the following postulates of kinetic
molecular theory of gases is incorrect?
1. There is no force of attraction between the
particles of a gas at ordinary temperature and
pressure
2. Particles of the gas move in all possible
directions in straight lines
3. At any particular time, different particles in the
gas have different speeds and hence different
kinetic energies
4. Gases consist of large number of different
particles (atoms or molecules) that are small
and so far apart on the average that the actual
volume of the molecules is negligible in
comparison to empty space between them
A balloon weighing 50 Kg is filled with 685.2 kg
of helium at 1 atm pressure and 25oC. What will
be its pay load if it displaces 5108 kg of air?
1. 4372.8 kg
2. 4422.8 kg
3. 5793.2 kg
4. 5843.2 kg
A gas describe by Van der Waal’s equation,
incorrect statement is..
1. behaves similar to an ideal gas in the limit of
large molar volumes.
2. behaves similar to an real gas in the limit of
large volumes.
3. is characterized by van der Waals’ coefficients
that are dependent on the identity of the gas but
are independent of the temperature.
4. has the pressure that is lower than the pressure
exerted by the same gas behaving ideally
At high temperature and low pressure, the
Van der Waal’s equation is reudced to
1.
2. PV = RT
3. P(V-b) = RT
4.
At high pressure, Van der Waal’s equation
becomes
1. PV = RT
2.
3.
4. PV = RT+Pb