Q.1.
A mixture of N2 and Ar gases in a cylinder contains 7 g of N2 and 8 g of Ar. If the total pressure of the mixture of the gases in the cylinder is 27 bar, the partial pressure of N2 is : ....[NEET 2020] [Use atomic masses (in g mol-1) : N = 14, Ar = 40]
-
36%
a) 15 bar
-
30%
b) 18 bar
-
23%
c) 9 bar
-
11%
d)12 bar
Q.2.
A gas at 350 K and 15 bar has molar volume 20 percent smaller than that for an ideal gas under the same conditions. The correct option about the gas and its compressibility factor (Z) is : [NEET 2019]
-
21%
a) Z > 1 and attractive forces are dominant
-
37%
b) Z > 1 and repulsive forces are dominant
-
35%
c) Z < 1 and attractive forces are dominant
-
7%
d) Z < 1 and repulsive forces are dominant
Q.3.
Given van der Waals constant for NH3, H2, O2 and CO2 are respectively 4·17, 0·244, 1·36 and 3·59, which one of the following gases is most easily liquefied ? [NEET 2018]
-
15%
a) O2 molecules
-
30%
b) H2
-
38%
c) NH3
-
18%
d) CO2
Q.4.
When helium is allowed to expand into vacuums, heating effect is observed. Its reason that...... [ CPMT 1987]
-
16%
a) Helium is an ideal gas
-
32%
b) Helium is an inert gas
-
37%
c) The inversion temperature of helium is very low
-
16%
d) The boiling point of helium is the lowest among the elements
Q.5.
" One gram molecule of gas at N.T.P. occupies 22.4 litres" This fact was derived from ..[ CPMT 1995]
-
5%
a) Dalton's theory
-
59%
b) Avogadro's hypothesis
-
10%
c) Berzelius hypothesis
-
27%
d) Law of gaseous volume
Q.6.
Vibrational energy is ... [ Pb. CET 1985]
-
50%
a) Partially potential and partially kinetic
-
11%
b) only potential
-
26%
c) only kinetic
-
13%
d) none of the above
Q.7.
According to kinetic theory of gases, the energy per mole of gas is equal to ... [ EAMCET 1985]
-
35%
a) 1.5RT
-
47%
b) RT
-
9%
c) 0.5RT
-
9%
d) 2.5RT
Q.8.
Which of the following is valid at absolute zero? [ Pb. CET 1985]
-
13%
a) Kinetic energy of the gas becomes zero but the molecular motion does not become zero
-
68%
b) Kinetic energy of the gas becomes zero and molecular motion also become zero
-
13%
c) Kinetic energy of the gas decreases but does not become zero
-
6%
d) none of above
Q.9.
Kinetic energy of a gas depends upon its ...... [ Bihar MADT 1982]
-
35%
a) Molecular mass
-
19%
b) Atomic mass
-
16%
c) Equivalent mass
-
29%
d) None of these
Q.10.
Which is not true in case of an ideal gas? [ CBSE PMT 1991]
-
12%
a) It cannot be converted into a liquid
-
29%
b) There is no interaction between molecules
-
32%
c) All molecules of the gas move with same speed
-
26%
d) At a given temperature, PV is proportional to the amount of the gas
Q.11.
Rate of diffusion of a gas is ....... [ CPMT 1987]
-
10%
a) directly proportional to its density.
-
13%
b) directly proportional to its molecular mass
-
42%
c) directly proportional to the square root of its molecular mass
-
35%
d) inversely proportional to the square root of its molecular mass
Q.12.
In van der Waal's equation of state for a non-ideal gas, the term that accounts for intermolecular forces is :.. CBSE PMT 1990]
-
64%
a) ( V - b )
-
7%
b) ( RT )-1
-
4%
c) RT
-
25%
d)
Q.13.
Absolute zero is defined as the temperature ... [ CBSE PMT 1990]
-
13%
a) at which all molecular motion ceases
-
27%
b) at which liquid helium boils
-
7%
c) at which ether boils
-
53%
d) all of the above
Q.14.
The average K.E. of an ideal gas in calories per mole is approximately equal to ....[ EAMCET 1989]
-
42%
a) Three times the absolute temperature
-
31%
b) Absolute temperature
-
4%
c) Two times the absolute temperature
-
23%
d) 1.5 times the absolute temperature
Q.15.
When ideal gas undergoes unrestrained expansion, no cooling occurs because the molecules .... [ IIT 1989]
-
20%
a) are above the inversion temperature
-
50%
b) exert no attractive force on each other
-
20%
c) do work equal to loss kinetic energy
-
10%
d) collide without loss of energy
Q.16.
In deriving the kinetic gas equation, use is made of the root mean square velocity of the molecules because it is ... [ Bihar MADT 1980]
-
16%
a) The average velocity of the molecules
-
16%
b) The most probable velocity of the molecules
-
42%
c) Unaffected by change in temperature
-
26%
d) The most accurate form in which velocity can be used in these calculations
Q.17.
Select one correct statement. In the gas equation, PV=nRT .. [ CBSE PMT 1992]
-
22%
a) n is the number of mole of a gas
-
28%
b) V denotes volume of one mole of the gas
-
22%
c) n moles of the gas have volume V
-
28%
d) P is the pressure of the gas when only one mole of gas is present.
Q.18.
Pressure remaining the same, the volume of a given mass of an ideal gas increases for very degree centigrade rise in temperature by definite fraction of its volume at ... [ CBSE PMT 1989]
-
32%
a) 0°C
-
21%
b) its critical temperature
-
42%
c) absolute zero
-
5%
d) its Boyle temperature
Q.19.
According to kinetic theory, for a diatomic molecule... [ MLNR 1991]
-
15%
a) the pressure exerted by the gas is proportional to the mean velocity of the molecules
-
25%
b) the pressure exerted by the gas is proportional; to the root mean square velocity of the molecules
-
30%
c) the root mean square velocity is inversely proportional to the temperature
-
30%
d) the mean translational kinetic energy of the molecules is proportional to the absolute temperature.
Q.20.
Which of the following gas will have highest rate of diffusion? [ CPMT 1990]
-
53%
a) NH3
-
26%
b) N2
-
16%
c) CO2
-
5%
d) O2
Explanation
Q.21.
Five grams each of the following gases at 87°C and 750 mm pressure are taken. Which of them will have the least volume? .. [ MLNR 1991]
-
28%
a) HF
-
17%
b) HCl
-
22%
c) HBr
-
33%
d) HI
Q.22.
The ratio γ for inert gases is .... [ AFMC 1990]
-
25%
a) 1.33
-
31%
b) 1.66
-
6%
c) 2.13
-
38%
d) 1.99
Q.23.
A bottle of ammonia and bottle of dry hydrogen chloride connected through a long tube are opened simultaneously at both ends, the white ammonium chloride ring formed will be ... [ IIT 1988]
-
39%
a) at the centre of the tube
-
22%
b) near the hydrogen chloride bottle
-
22%
c) near the ammonia bottle
-
17%
d) through the length of the tube
Q.24.
In the equation PV=nRT, which one cannot be the numerical value of R? [ BIT 1987]
-
10%
a) 8.31 ×107 erg K-1 mol-1
-
43%
b) 8.31 × 107 dyne cm K-1 mol-1
-
29%
c) 8.31 J K-1 mol-1
-
19%
d) 8.31 atm. K-1 mol-1
Q.25.
Gases deviate from the ideal gas behaviour because their molecules ..
-
18%
a) posses negligible volume
-
41%
b) have force of attraction between them
-
29%
c) are polyatomic
-
12%
d) are not attracted to one another
Q.26.
With increase of pressure, the mean free path [ Pb. CET 1985]
-
33%
a) decreases
-
40%
b) increases
-
13%
c) does not change
-
13%
d) become zero
Q.27.
In a closed flask of 5 liters, 1.0g of H2 is heated from 300 to 600 K. which statement is not correct? [ CBSE PMT 1991]
-
6%
a) Pressure of the gas increases
-
29%
b) The rate of collision increases
-
41%
c) The number of molecules of gas increases
-
24%
d) The energy of gaseous molecules increases
Q.28.
At constant temperature, in a given mass of an ideal gas ... [ CBSE PMT 1991]
-
31%
a) The ratio of pressure and volume always remain constant
-
25%
b) Volume always remains constant
-
6%
c) Pressure always remains constant
-
38%
d) The product of pressure and volume always remains constant
Q.29.
Any gas shows maximum deviation from ideal gas at ... [ CPMT 1991]
-
28%
a) 0°C and 1 atm. pressure
-
33%
b) 100°C and 2 atm. pressure
-
28%
c) -100°C and 5 atm pressure
-
11%
d) 500°C and 1 am. pressure
Q.30.
A closed vessel contains equal number of nitrogen and oxygen molecules at a pressure of P mm. If nitrogen is removed from system then the pressure will be ... [ MP PMT 1985]
-
15%
a) P
-
20%
b) 2P
-
50%
c) P/2
-
15%
d) P2