States of Matter – I

1) In order for the volume of 800 c.c. of a gas to be reduced to 25%, to what temperature is the gas is to be cooled if the initial temperature is 270at constant P?

75 K
b) 225 K
c) 300 K
d) -750 c

2) Under identical conditions how many times faster will helium diffuse out than argon ?

a) 10
b) 7.32
c) 3.66
d) 3.1

3) Air contains 20% by volume of oxygen. The volume of air required to burn 5 L of Ethyne is

6.25 L
b) 62.5 L
c) 7.5 L
d) 12.5L

4) The volume of 800c.c. of a gas is to be reduced by 25%. If the initial temperature is 270c what must be the final temperature if P is constant?

b) 22.50C
c) -480C
d) -225K

5) The average kinetic energy of oxygen molecules at S.T.P will be

greater than that of H 2 at STP
b) greater than that of CI 2 at STP
c) same as that of H 2 and CI 2 at STP
d) less than that of H 2 at STP

6) The temperature in 0C when a certain volume of gas at STP is expanded to occupy thrice its volume at constant pressure is

a) 819
b) 546
c) 891
d) 564

7) What is the pressure in atmospheres of H 2 in a 10 L flask containing 1 mol of H 2 and 2 mol of helium at 270C?

a) 2.46
b) 4.92
c) 7.38
d) 0.246

8) A mixture of 0.1 mol of H 2 and 0.2 mol of Helium has a total pressure of 1.2 atm. What is the partial pressure of Helium?

a) 1.2
b) 0.24
c) 0.8
d) 0.4

9) If we consider two different gases at the same temperature which of the following statements is true?
a) Their pressures are equal
b) Their average molecular velocities are equal
c) their average kinetic energies are equal
d) the number of moles are equal

10) The Boltzmann constant is
a) 8.31 JK-1 mol -1
b) 1.38 * 10-23JK-1 mol -1
c) 8.31 JK -1 molecule
d) 1.38 * 10 -23 JK -1 mol -1

11) The volume of oxygen at STP obtained by heating 244g of KCIO3 is
a) 3 L
b) 0.672 L
c) 6.72L
d) 67.2 L

12) The pressure of 4L of O2 gas is doubled while its absolute temperature increased by 25%. The volume of oxygen will be
a) 3L
b) 2.5L
c) 2L
d) 4L

13) We have 2.8 g of N 2 and 2.8g of H 2 at S.T.P. Which of the following statements is true?
a) both N 2 and H 2 will have the same volume
b) N 2 has a higher volume
c) N 2 has a lower volume
d) the number of moles of H 2 and N 2 are equal

14) The atomic mass of an element is
a) the actual mass of one atom of the element
b) The relative mass of an atom of the element
c) The average relative mass of different atoms of the element
d) different from the mass number of the element

15) At N.T.P 5.6 litres of a gas weigh 8 gram. The vapour density of the gas is
a) 32
b) 40
c) 16
d) 8

16) 10 g of hydrofluoric acid gas occupies 5.6 litres of volume at STP. If the empirical formula of the gas is HF, then its molecular formula in the gaseous state will be
a) HF

17) In a face centred cubic lattice, the number of nearest neighbours for a given lattice point is
a) 6
b) 8
c) 12
d) 14

18) If the coordination number of an element in its crystal lattice is 8, then the packing is
a) fcc
b) hcp
c) bcc
d) none of these

19) In a hexagonal close packing in two layers one above the other, the coordination number of each sphere will be
a) 4
b) 6
c) 8
d) 9

20) The coordination number of a cation occupying a tetrahedral hole is
a) 4
b) 6
c) 8
d) 12

21) The type of structure assumed by an ionic compound is determined by the
a) Relative number of each kind of the ions
b) Relative sizes of each kind of ion
c) Both (a) and (b)
d) None of these

22) The limiting radius ratio for the tetrahedral shape is
a) 0 to 0.155
b) 0.115-0.225
c) 0.225-0.414
d) 0.414-0.732

23) For an octahedral arrangement the lowest radius ratio limit is
a) 0.155
b) 0.732
c) 0.414
d) 0.225

24) The radius ratio of the cation to the anion of an ionic compound is 0.4. Its structural arrangement is
a) Planar triangular
b) Tetrahedral
c) Octahedral
d) Body-centred cubic

25) If the radius ratio is in the range of 0.414-0.732, then the co-ordination number will be
a) 2
b) 4
c) 6
d) 8

26) The structure of TICI is similar to CsCI. What would be the radius ratio in TICI?
a) 0.155-0.225
b) 0.225-0.414
c) 0.414-0.732
d) 0.732-1.000

27) At the limiting value of radius ratio r+/r , the
a) Forces of attraction are larger than the forces of repulsion
b) Forces of attraction are smaller than the forces of repulsion
c) Forces of attraction and repulsion are just equal
d) None of these

28) The ratio of radius (R) of a sphere to the radius (r) of an octahedral void is
a) 1:1
b) 1:0.414
c) 1:0.225
d) 0.414:1

29) The radius ratio of KF is 0.98. The structure of KF is of the type
a) NaCI
b) ZnS
c) CsCI
d) Graphite

30) In the NaCI crystal r+/r ratio is:
a) 0.4
b) 0.98
c) 1.0
d) 0.52

31) If the distance between Na+ and CI- ions in NaCI crystal is a pm, what is the length of the cell edge?
a) 2a pm
b) a/2 pm
c) 4a pm
d) a/4 pm

32) Potassium fluoride has an NaCI-type structure. What is the distance between K+ and F ions if the cell edge isa cm?
a) 2a cm
b) a/2 pm
c) 4a pm
d) a/4 pm


The formula for determination of the density of a unit cell is :


The ionic radii are in the order

35) An element has bcc structure having unit cells . The number of atoms in these cells is


Which one of the following statements is incorrect about the rock salt type of structure?
a) It has a free arrangement of Na+
c) A unit cell of NaCI consists of four NaCI units
d) All halides of alkali metals have rock-salt type structure

37) In sodium chloride, ions form a ccp arrangement. Which site will ions occupy in this structure?
a) Cubic
b) Tetragonal
c) Octahedral
d) Trigonal bipyramidal

38) Air contains nearly 20% oxygen by volume. The volume of air needed for the complete combustion of 100 cc of acetylene will be
a) 500cc
b) 100cc
c) 250cc
d) 1250cc

39) @ The volume of produced at STP by combustion of 66.7 g of sulphur containing 4% sand by weight will be
a) 33.6 L
b) 22.4 L
c) 11.2L
d) 44.8L

40) Four one litre flasks are separately filled with the gases hydrogen, helium, oxygen and ozone at the same room temperature and pressure. The ratio of total number of atoms of these gases present in the different flasks would be
a) 1:1:1:1
b) 1:2:2:3
c) 2:1:2:3
d) 3:2:2:1

41) Which of the following pairs of crystals are isomorphous?

42) @ The ratio of and of a gas is 1.4. The number of atoms of the gas present in 11.2 litres of it at NTP will be

43) @ 1.12 ml of a gas is produced at S.T.P by the action of 4.12 mg of alcohol, ROH, with methyl magnesium iodide. The molecular mass of alcohol is
a) 16.0
b) 41.2
c) 82.4
d) 156.0

44) Two containers P and Q of equal volume ( 1 litre each) contain 6 g of respectively at 300 K and 1 atmosphere. Then
a) The number of molecules in P is less than that in Q
b) The number of molecules in Q is less than that in P
c) The number of molecules in P and Q are same
d) Either (a) or (b)

45) The temperature and pressure at which ice, liquid water and water vapour can exist together are

46) Which of the following is true about the gaseous state?
a) Thermal energy = Molecular attraction
b) Thermal energy >> Molecular attraction
c) Thermal energy < Molecular attraction
d) Molecular forces >>those in liquids

47) The kinetic energy of molecules is highest in
a) Gases
b) Solids
c) Liquids
d) Solutions

48) Which one of the following statement is incorrect?
a) A barometer is used for the measurement of the pressure of a gas

49) Torr is the unit of
a) Temperature
b) Pressure
c) Volume
d) Density

50) Which of the following relations for expressing the volume of a sample is not correct?

51) The temperature at which the Celsius and Fahrenheit scales give the same reading is

52) Mountaineers carry oxygen cylinders with them because the
a) Density of air is higher at high altitudes
b) Density of air is low at high altitudes
c) Air is less pure at high altitudes
d) Air contains no oxygen at high altitudes

53) A gas at 298 K is shifted from a vessel of 250 cm 3 capacity to that of 1L capacity. The pressure of gas will
a) Become double
b) Becomes four times
c) Decrease to half to the original value
d) Decrease to one-fourth of the original value

54) Which one of the following will give a linear plot at constant pressure?
a) V vs T
b) V vs 1/T
c) T vs 1/T
d) None of these

55) When a gas is compressed at constant temperature
a) The speeds of the molecules increase
b) The number of collisions between the molecules increase
c) The speeds of the molecules decrease
d) The number of collisions between the molecules decrease

56) The pressure of a gaseous system can be increased by
a) increasing the volume of the container
b) decreasing the temperature at constant volume
c) removing some molecules
d) initiating a reaction that produces more molecules than are consumed

57) When two ideal gases are heated from 20 to 40o C at constant pressure, their volumes
a) increase by the same magnitude
b) become double
c) increase in the ratio of their molecular masses
d) increase but to different extent

58) In the equation of state of an ideal gas PV = nRT, the value of the universal gas constant would depend only on
a) The nature of the gas
b) The pressure of the gas
c) The temperature of the gas
d) The units of the measurement

59) Which of the following shows explicitly the relationship between and ?
d) PV = K

60) The density of a gas is 1.4 g/ml at one atmosphere pressure and 27 o C. At what pressure will the gas have density thrice this value, if the temperature is kept constant ?
a) same temperature
b) 2 atmosphere
c) 3 atmosphere
d) 4.2 atmosphere

61) If the absolute temperature of a gas is doubled and the pressure is reduced to one-half, the volume of the gas will
a) remain unchanged
b) be doubled
c) increase four- fold

62) When the universal gas constant R is divided by (No) their ratio is called the
b) Rydberg constant
c) Boltzmann constant

63) Which of the following expressions represents correctly the variation of density of an ideal gas with change in temperature?

64) The molar volume of CO2 is maximum at
a) NTP

65) The gas constant R is a constant
a) Only for real gases
b) Only for ideal gases
c) Both for real and ideal gases
d) Neither for real nor for ideal gases

66) In the gas equation PV/3 = RT, V represents the
a) volume of container
b) volume of 1 mole of a gas
c) volume of 1/3 mole of a gas
d) volume of 3 moles of a gas

67) The numerical value of N/n (where N is the number of molecules in a given sample of gas and n is the number of moles of the gas) is :
a) 8.314
c) 0.0821

68) A gaa occupies10 litres at STP. Which of the following new conditions keep the volume constant?
a) 273 K and 2 atm. Pressure

69) Aqueous tension of water (pressure exerted by the water vapour) depends upon
a) the amount of water taken
b) the temperature only
c) both on the amount of water and temperature
d) neither the temperature nor the amount of water but on certain other factors

70) The kinetic energy of one mole of helium gas at is
a) 300 cal
b) 600 cal
c) 900 cal
d) 200 cal

71) The ratio of the partial pressure of a gaseous component to the total vapour pressure of the mixture is equal to the
a) mass of the component
b) mole fraction of the component
c) mass % of the component
d) molecular mass of the component

72) The rate of diffusion of a gas is proportional to

73) Which one of the following represents the kinetic gas equation?
a) PV = nRT

74) By how much would the temp. of a gas increase when the r.m.s velocity of gas molecules in a closed container of fixed volume is increased from to
a) 0.5 times
b) 2 times
c) 4 times
d) 16 times

75) According to the kinetic theory of gases, the root mean square velocity is directly proportional to
a) T

76) Which one of the following relationships is correct?

77) The kinetic energy for 14 grams of nitrogen gas at is nearly (mol. mass of nitrogen = 28 and gas constant )
a) 1.0 J
b) 4.15 J
c) 2493 J
d) 3.3 J

78) In van der Waal’s equation,
a) b is the volume occupied by the gas molecules
b) b is four times the volume occupied by the gas molecules
c) b is the correction factor for intermolecular attraction
d) b is constant for all gases

79) Which of the following gases would have the highest R.M.S velocity at 25 o C?
a) Oxygen
b) Carbon dioxide
c) Sulphur dioxide
d) Carbon monoxide

80) The units of the are

81) The units of the are
a) atmosphere
b) joules

82) At what temperature will the average velocity of molecules have same value that has at 300 K ?
a) 300 K
b) 600 K
c) 900 K
d) 1200 K

83) The kinetic theory of gases predicts that the total kinetic energy of a gaseous assembly depends on the
a) Pressure of the gas
b) Temperature of the gas
c) Volume of the gas
d) Pressure, temperature and volume of the gas

84) The velocity possessed by the greatest number of gaseous molecules is the
a) Average velocity
b) Most probable velocity
c) R.M.S velocity
d) None of these

85) The value of is the lowest for :
a) Helium
b) Hydrogen
c) Nitrogen
d) Chlorine

86) The molecules of which of the following gases have the largest mean average K.E. at 250o C?
a) Ar
b) CO
c) He
d) All have the same K.E

87) For H 2 gas, the compressibility factor, Z = PV/n RT is
a) equal to 1
b) equal to 0
c) always greater than 1
d) initially less than 1 and then becomes greater than 1 at high pressures

88) A certain volume of gas exerts some pressure on walls of container at a constant temperature. It has been found that by reducing the volume of the gas to half of its original value, the pressure becomes twice the initial value at constant temperature. This is because
a) the weight of the gas increases with pressure
b) velocity of gas molecules decreases
c) more gas molecules strike the surface per second
d) gas molecules attract one another

89) Which of the following is not correct in the case of the kinetic theory of gases?
a) Gases are made up of small particles called molecules
b) The molecules are in constant motion
c) When molecules collide, they lose energy
d) When the gas is heated, the molecules move faster

90) Which of the following is true about the mass of molecules m and urms?

91) Gases can be compressed to a greater extent because
a) its molecules are elastic
b) There is no gap between molecules
c) These are lighter than liquids
d) There is a large space between the molecules

92) An increase in temperature causes an increase in the pressure of a gas because
a) it causes the molecules to combine together
b) it decreases the average velocity of the molecules
c) it increases the average velocity of the molecules
d) it increases the number of collisions between the molecules

93) The kinetic energy of one mole of any gas depends upon the
a) pressure of the gas
b) nature of the gas
c) volume of the gas
d) absolute temperature of the gas

94) Which of the following is the correct relation for the root mean square velocity?

95) The average velocity of gas molecules is equal to

96) The most probable velocity is expressed as

97) The excluded volume or non-compressible volume of a gas is …….. times the actual volume of a gas
a) 2
b) 4
c) 3
d) 0.5

98) A real gas obeying the van der Waal equation will resemble an ideal gas if the
a) constants a and b are small
b) a is large and b is small
c) a is small and b is large
d) constants a and b are large

99) The molecules of which of the following gases has the highest speed?
d) They have the same speed

100) The pressure of real gases is less than that of an ideal gas because of the
a) increase in the number of collisions
b) finite size of particles
c) intermolecular attraction
d) increase in kinetic energy of the molecules


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