33 Years NEET-AIPMT Chapterwise Solutions - Physics 2020

Kinetic Theory
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101
CHAPTER
13
Kinetic Theory
13.3 Behaviour of Gases
1. A given sample of an ideal gas occupies a volume
V at a pressure P and absolute temperature T. The
mass of each molecule of the gas is m. Which of the
following gives the density of the gas ?
(a) P/(kT)
(b) Pm/(kT)
(c) P/(kTV) (d) mkT (NEET-II 2016)
2. Two vessels separately contain two ideal gases A and
B at the same temperature, the pressure of A being
twice that of B. Under such conditions, the density
of A is found to be 1.5 times the density of B. The
ratio of molecular weight of A and B is
(a) 2 (b) 1/2
(c) 2/3 (d) 3/4 (2015)
3. In the given (V – T) diagram, what is the relation
between pressures P 1
and P 2
?
(a) P 2
< P 1
(b) Cannot be predicted
(c) P 2
= P 1
(d) P 2
> P 1
(NEET 2013)
4. At 10°C the value of the density of a fixed mass of an
ideal gas divided by its pressure is x. At 110°C this
ratio is
10
(a)
110 x (b) 283
383 x
(c) x (d) 383
283 x (2008)
5. The equation of state for 5 g of oxygen at a pressure
P and temperature T, when occupying a volume V,
will be
(a) PV = (5/32)RT (b) PV = 5RT
(c) PV = (5/2)RT (d) PV = (5/16)RT
(where R is the gas constant) (2004)
6. The value of critical temperature in terms of van der
Waals’ constant a and b is given by
(a)
a
TC = 8
27 Rb
a
(c) TC = 2 Rb
a
(b) TC = 27
8Rb
a
(d) TC = 27 Rb (1996)
7. Three containers of the same volume contain three
different gases. The masses of the molecules are
m 1
, m 2
and m 3
and the number of molecules in
their respective containers are N 1
, N 2
and N 3
. The
gas pressure in the containers are P 1
, P 2
and P 3
respectively. All the gases are now mixed and put
in one of these containers. The pressure P of the
mixture will be
(a) P < (P 1
+ P 2
+ P 3
) (b) P P 1 +
=
P 2 + P 3
3
(c) P = P 1
+ P 2
+ P 3
(d) P > (P 1
+ P 2
+ P 3
) (1991)
8. Two containers A and B are partly filled with water
and closed. The volume of A is twice that of B and it
contains half the amount of water in B. If both are
at the same temperature, the water vapour in the
containers will have pressure in the ratio of
(a) 1 : 2 (b) 1 : 1
(c) 2 : 1 (d) 4 : 1 (1988)
13.4 Kinetic Theory of an Ideal Gas
9. Increase in temperature of a gas filled in a container
would lead to
(a) decrease in intermolecular distance
(b) increase in its mass
(c) increase in its kinetic energy
(d) decrease in its pressure (NEET 2019)
10. At what temperature will the rms speed of oxygen
molecules become just sufficient for escaping from
the Earth’s atmosphere?
(Given : Mass of oxygen molecule (m) = 2.76 × 10 –26 kg,
Boltzmann’s constant k B
= 1.38 × 10 –23 J K –1 )
(a) 2.508 × 10 4 K
(c) 5.016 × 10 4 K
(b) 8.360 × 10 4 K
(d) 1.254 × 10 4 K
(NEET 2018)