1. Compressibility factor (Z) is equal to
Ans: (3)
Explanation:
2. One rupee coin can float on the surface of mercury due to the combination of buoyant force and
1) viscosity 2) surface tension
3) tailing of mercury 4) both 1 and 2
Ans: (2)
Explanation: due to buoyant force and surface tension.
3. Partial pressures of gases in a container during effusion is
Ans: (4)
Explanation: rate of effusion 
As SO2 has high molar mass, it effuses less quantity. So more gas is remained in the container & causes high partial pressure.
4. Most probable speed of a gas is 1000 cm/sec. Hence average speed and R.M.S. speed of the gas under similar conditions are respectively
1) 1128 cm/sec, 1224 cm/sec 2) 1182 cm/sec, 1242 cm/sec
3) 1290 cm/sec, 1580 cm/sec 4) 1580 cm/sec, 1450 cm/sec
Ans: (1)
Explanation:
5. Incorrect statement among the following is
1) Water boils at low temperature on hills.
2) Boiling occurs even liquid is heated in a closed vessel.
3) Due to surface tension liquid get the shape of the container.
4) When a liquid flows over a fixed solid surface, the layer of molecules in the immediate contact of surface is stationary.
Ans: (2)
Explanation: Boiling does not occur when liquid is heated in a closed vessel.
6. 
1) 3 2) 8 3) 
4) 2.7
Ans: (3)
Explanation:
7. A gaseous mixture of O2 and N2 are in the ratio 1 : 14 by weight. The ratio of the molecules is
1) 32 : 7 2) 7 : 32 3) 16 : 1 4) 1 : 16
Ans: (4)
Explanation:
8. Van der Waal's constants 'a' and 'b' for H2 are 0.246 lit2 atm mol-2 and 0.0267 lit mol-1 respectively. Boyle's temperature of H2 gas is
1) 224.4 K 2) 112.2 K 3) 61.1 K 4) 173.4 K
Ans: (2)
Explanation:
9. If the compressibility factor (Z) of a gas is less than unity at STP. So Vm is
1) < 22.4 lit 2) = 22.4 lit 3) > 22.4 lit 4) 1 lit
Ans: (1)
Explanation:
10. The rms speed of Hydrogen is 
times the rms speed of N2. If T is the temperature of the gas, then
Ans: (3)
Explanation:
11. At T(K), the ratio of kinetic energies of 4 g of H2 and 8 g of O2 is
1) 1 : 4 2) 4 : 1 3) 2 : 1 4) 8 : 1
Ans: (4)
Explanation:
12. The compressibility factor for a real gas at high pressure is
Ans: (2)
Explanation:
13. a and b are Van der Waal's constants for the gases. Cl2 gas is more easily liquified than Ethane because
1) a & b for Cl2 > a & b for Ethane
2) a & b for Cl2< a & b for Ethane
3) a for Cl2< a for C2H6 but b for Cl2 > b for C2H6
4) a for Cl2 > a for C2H6 but b for Cl2< b for C2H6
Ans: (4)
Explanation: a is due to force of attraction and b is due to size of the molecules.
∴ a(Cl2) > a(C2H6) and b(Cl2) < b(C2H6).
14. The molecular velocity of any gas is
Ans: (3)
Explanation:
15. If 10-4 dm3 of water is introduced into a 1.0 dm3 flask at 300 K, the no. of moles of water are in the vapour phase when equilibrium established is (vapour pressure of water at 300 K = 3170 Pa)
1) 1.53 × 10-2 mol 2) 1.27 × 10-3 mol
3) 4.46 × 10-2 mol 4) 5.56 × 10-3 mol
Ans: (2)
Explanation:
16. Standard ambient temperature and pressure means
1) 298.15 K & 1 bar 2) 298.15 K and 105 Pa
3) both 1 & 2 4) 273.15 K & 101.325 K.Pa
Ans: (3)
Explanation: 1 bar = 105 Pa; 1 atm = 101.325 K Pa
STP = 273.15 K & 1 atm
SATP = 298.15 K & 1 bar
17. The gram molar volume of an ideal gas at STP and SATP are respectively
1) 22.414 lit & 24.789 lit 2) 24.789 lit & 22.414 lit
3) 22.414 lit & 22.414 lit 4) 24.789 lit & 24.789 lit
Ans: (1)
Explanation: molar volume at STP = 22.414 lit
SATP = 24.789 lit
18. In dipole - dipole interaction, energy between stationary molecules is proportional to x and that between rotating polar molecules is proportional to y, where x & y are respectively
Ans: (2)
Explanation: Conceptual.
19. The correct increasing order of critical temperature values of N2, H2O, NH3 and CO2 is
1) N2< NH3< H2O < CO2 2) CO2< N2< H2O < NH3
3) N2< CO2< NH3< H2O 4) NH3< H2O < CO2< N2
Ans: (3)
Explanation: Tc of N2 = 126 K, CO2 = 304 K, NH3 = 406 K, H2O = 647 K.
20. The correct match of the following is
1) attraction between 2 temporary dipoles - London force
2) attraction between 2 permanent dipoles - Dipole-dipole force
3) attraction between molecule having permanent dipole & molecules lacking permanent Dipole - Dipole induced dipole force
4) all are correct
Ans: (4)
Explanation: all are correct.
21. The correct order of no. of molecules having speeds
1) nmp > nav > nRMS 2) nav = nRMS = nmp
3) nav > nRMS > nmp 4) nRMS > nav > nmp
Ans: (1)
Explanation: According to graph between distribution of molecular speeds and their variation with molar masses : order of speeds is Vrms > Vav > Vmp
Order of no. of molecules possessing velocities : nmp > nav > nrms.
22. Which of the following mixture(s) do not obey the Dalton's law is/ are
1) NO + O2 2) H2 + Cl2 3) CO + Cl2 4) all the above
Ans: (4)
Explanation: all the mixtures are reacting, do not obey Dalton's law.
23. Equal masses of Methane and Oxygen are mixed in an empty container at 25°C. The fraction of the total pressure exerted by Oxygen is
Ans: (3)
Explanation: If we take 1 gram of each gas
24. Surface tension vanishes at
1) Triple point 2) Critical point 3) Boiling point 4) Melting point
Ans: (2)
Explanation: At critical temperature, as the meniscus between the liquid and its vapour disappears. So surface tension becomes equal to zero.
25. H2 diffuses 6 times faster than gas "A". The molar mass of the gas is
1) 72 2) 36 3) 64 4) 24
Ans: (1)
Explanation:
