IIT JEE MCQ Quiz Hub

1. Which of the following is false about gases
The molecules possess random movement in all directions
Gases intermix freely without the help of external agency
They are highly compressible
They possess definite volume.

2. wo gases X and Y are at same temperature and pressure. The reduced temperature of X is below unity while that of Y is above unity. Thus
X can be liquefied by compression but not Y
Y can be liquefied by compression but not X
both X and Y can be liquefied by compression
none of the statement is correct.

3. Liquefication of gases cannot be achieved by
cooling
compressing the gas at all temperatures
compressing the gas as well as cooling
compressing the gas below critical temperature.

4. A pressure of 0.101325 bar when expressed in atmospheres represents
0.01 atm
1 atm
0.1 atm0.1 atm
10 atm.

5. Which of the following statement is false?
The product PV for fixed amount of gas is independent of temperature.
Molecules of different gases have same KE at a given temperature.
The gas equation is not valid at high pressure and low temperature.
The gas constant per molecule is known as Boltzman constant.

6. A rubber balloon permeable to all isotopic forms of hydrogen is filled with heavy hydrogen and placed in tank of pure hydrogen. After some times the balloon will
shrink in size
expand
remain as such
shrink to half of its size.

7. The value of universal gas constant depends upon
temperature of the gas
volume of the gas
number of moles of gas
none of these.

8. At constant volume for a foxed number of gas moles the pressure of the gas increases with the rise in temp. because of
increase in average molecular speed
increased rate of collisions amongst molecules
increase in molecular attraction
decrease in mean free path.

9. An ideal gas is at pressure P and temperature T in a box which has been placed in another evacuated large container. The inner box is pricked so that the gas inside it starts escaping out. What is correct?
the temperature falls
the temperature rises
the temperature remains
the sameunpredictable.

10. The bottle of liquid ammonia is cooled before opening the seal so as to lower its
vapour pressure
surface tension
viscosity
extent of H-bonding.

11. The vapour density a diatomic gas with homoatomic molecules is 25. The atomoc mass of a gas will be
150
25
75
22

12. Under which of the following conditions the real gases will approach the behaviour of ideal gas?
15 atm 200 K
0.5 atm 500 K
1 atm 273 K
15 atm 500 K.

13. For ideal gas isochors refer to the graphs between
V and T at constant P
P and T at constant V
P and V at constant T
V/T and T at constant P.

14. One litre of gas weighs 2 g at 300 K and 1 atm pressure. If the pressure is made 0.75 atm and temperature is brought down to 250 K the gas will occupy a volume of
2 L
1.11 L
2.22 L
0.7 L.

15. The magnitude of van der Waals forces depends upon
molecular size
number of electrons in the molecule
polarisability of molecules
all the above factors.

16. Which of the following do not pertain to the postulates of kinetic theory of gases?
Molecular collisions are perfectly elastic
Gas molecules move at random with ever changing speeds
Molecular collision against the wall are responsible of gas pressure.
KE of a gas is given by the sum of 273 and temperature in celcius scale.

17. Real gases deviate from ideal behaviour because the molecules
are colourless
attract each other
contain covalent bonds
show Brownian movement.

18. Rate of diffusion of a gas is
directly proportional to its density
directly proportional to its molecular mass
directly proportional to the square root of its molecular mass
inversely proportional to the square root of its molecular mass.

19. For ideal gases isotherm refers to the
gases at same temperatures
gases at same pressure
gases having same heat capacities
plot of us V at constant T.

20. The temperature of ideal gas can be increased by
decreasing the volume and pressure but keeping the amount constant
increasing the pressure but keeping the volume and amount constant
decreasing the amount but keeping the volume and pressure constant
any of b or c operation.

21. The state in which 99% matter of the universe exists is
Plasma
Solid
Gaseous
Liquid.

22. The densities of two gases are in the ratio of 1: 16. The ratio of their rates of diffusion is
16:01
4:01
1:04
1:16

23. Which among the following samples of gases contains Avogadro number of atoms at S.T.P.?
2 g of Helium
11.2 L of carbon monoxide
11.2 L of sulphur dioxide
1 mol of phosphine.

24. The dimensions of pressure are some as that of
Energy
Energy per unit volume
Force per unit area
Force per unit volume.

25. When ideal gas undergoes unstrained expansion no cooling occurs because the molecules
are above inversion temperature
exert no attractive force on each other
work equal to loss in kinetic energy
collide without loss of energy.

26. 1000 ml of a gas A at 600 torr and 500 ml of gas B at 800 torr are placed in a 2L flask. The final pressure in atmosphere is
2000
1000
500
0.657.

27. The average distance traveled by the molecule between successive collisions is called
collision path
mean free path
collision diameter
collision distance.

28. If volume of two moles of ideal gas at 540 K is 44.8 L then its pressure will be
1 atm
2 atm
3 atm
4 atm.

29. A vessel containing gas at a pressure of 60 cm of Hg was connected to arm A of open end manometer. The atmospheric pressure was recorded as 74 cm of Hg. If mercury in arm A stands at 84.5 cm height the mercury in arm will stand at
70.5 cm
74 cm
24.5 cm
88 cm.

30. Hydrogen diffuses 6 times faster than gas X. The molecular mass for X will be
72
140
144
100

31. Four soldered ampules of equal volumes contain nitrogen ozone chlorine and helium at ordinary conditions. The largest number of atoms will be found in the ampule containing
chlorine
ozone
helium
nitrogen.

32. Two flasks of equal capacity contain argon and chlorine gases respectively at room temperature. What is true about them?
Both contain same number of atom
Cl atoms are half of the Ar atoms
Cl atoms are double the number of Ar atoms
Chlorine molecules are double the number of argon molecules.

33. The behaviour of a real gas approaches ideal behaviour at
low temperature low pressure
low temperature high pressure
vlow temperature high pressure
high temperature low pressure.

34. 1 g of Zn was treated with each of excess of sulphuric acid and excess of NaOH separately. The ratio of the volumes of hydrogen evolved is
1:01
1:02
9:04
2:01

35. The temperature at which real gas exhibits ideal behaviour over a wide range of pressure is called
Inversion temperature
Boyle temperature
Reduced temperature
Critical temperature.

36. Critical temperature of the gas refers to the temperature
at which it occupies a volume of 22.4 L
at which if gets liquefied at 1 atmosphere
below which it always exists as liquid
above which it always exists as gas.

37. 10 g of each of the following gases were taken HF HCl HBr HI under similar conditions then
all will have same volume
HF will have largest volume
HI will have largest volume
HBr will have lowest volume.

38. Which of the following pairs of gas will diffuse at the same rate under similar conditions?
carbon dioxide and nitrous oxide
carbon dioxide and nitrogen dioxide
carbon dioxide and nitric oxide
carbon monoxide and carbon dioxide.

39. The value of critical volumes of four gases A B C D are 0.025 L 0.312 L 0.245 L and respectively. The gas with larger value of van der Waal constant b is
A
D
B
unpredicatable.

40. Same gas is confined to two containers A and B. The pressure volume and temperature (K) of gas in A are three times as compared to that in B. If the mass of gas in A is x g then the mass in B would be
x g
0.3x g
0.5x g
3x g.

41. Each of the four species hydrogen sulphide (I) protium oxide (II) hydrogen chloride (III) and chlorine (IV) at S.T.P. have been put into four separate vessel each of one litre capacity. The largest number of molecules are present in
i
ii
iii
All will have same no. of molecules.

42. The vapour density of gas X is 4 times that of Y. If molecular mass of X is
M/2
4M
M/4
2M.

43. The distance between the centres of the molecules at the closest approach is called
collision diameter
van der Waal distance
can der Wall radius
covalent radius.

44. Three flasks of 2 L capacity were separately filled with argon oxygen and ozone respectively under similar conditions. The ratio of number of atoms in the flasks is
1:01:01
1:02:03
3:02:01
2:02:03

45. Which of the following will not change the r.m.s. if the gas molecules?
Change in temperature
Change in volume at constant T
Change in volume at constant T
Change in number of gas molecules.

46. Which among the following contains Avogadro number of molecules?
36 g of water vapours
49 g of hydrogen sulphate
17 g of ammonia
4.4 g of carbon dioxide.

47. Real gases deviate from ideal behaviour because their molecules
cause repulsive interactions on one another
cause attractive interaction on one anotherare polyatomic
do not undergo elastic collisions.
None of them

48. Three different gases X Y Z of molecular masses 32 64 71 were enclosed in a vessel at constant temperature till equilibrium is reached. Which of the following statement is/are true?
Gas X will be at the top of the vessel
Gas Y will be at the top of the vessel
Gas X will be at the bottom and Z will be at the top
Gases will form homogeneous mixture.

49. The van der Waal constant b is equal to
four times the volume of 1 mol of gas
the molecular volume of 1mol of gas
four times the actual volume of molecules contained in 1 mol of gas
twice the molecular volume of 1 mol of gas.

50. Pick up correct answer among the following about Boyles temperature
The ratio P/T approaches unity
The ratio RT/PV approaches unity
The ratio PV/RT approaches unity
The ratio PV/RT approaches zero.

51. The mixture of three gases X (density 0.09) Y (density 0.178) and Z (density 0.42) is enclosed in a closed vessel at constant temperature. When equilibrium is establisted the
gas X will be at the top of the vessel
gas Y will be at the top of the vessel
gases X Y Z will constitute homogeneous mixture throughout the vessel
gas Y will be at the bottom of the vessel.

52. 500 ml of gas A at 1000 torr and 1000 ml of gas at 800 torr ate placed in an empty container of 2 L capacity. The pressure in the container would be
100 torr
2400 torr
650 torr
1800 mm.

53. The rate of diffusion of methane at certain temperature is 2 times that of gas X. The molecular mass of X is
64
32
4
8.0.

54. Which of the following is not the postulate of the kinetic theory of gases?
gas molecules are in a permanent state of random motion
pressure of gas is due to molecular impacts on the walls
the molecules are perfectly elastic
the molecular collisions are elastic.

55. A balloon containing methane is pricked with a sharp needle and quickly plunged into a tank of hydrogen at same pressure. After sometime the balloon will
get enlarged
get collapsed
remain as beforereduce to half of its
original size.

56. A real gas which obeys van der Waals equation will approach ideal behaviour if
a is large b is small
a is small b is large
a and b both are large
a b are negligibly small.