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InterviewSolution
This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 51. |
STATEMENT-1 : The gases He and `H_(2)` are very different in their behaviour at any temperature and pressure but their compressibility factors are nearly the same at the critical point. STATEMENT-2 : They have nearly the same critical constant.A. If both the statement are TRUE and STATEMENT-2 is the correct explanation of STATEMENT-1B. If both the statement are TRUE but STATEMENT-2 is NOT the correct explanation of STATEMENT-1C. If STATEMENT-1 is TRUE and STATEMENT-2 is FALSED. If STATEMENT-1 is FALSE and STATEMENT-2 is TRUE |
| Answer» Correct Answer - C | |
| 52. |
Select the wrong statement about real gases .A. Larger is `T_(c)//P_(c)` larger will be excluded volume .B. `T_(c)gtT_(i)gtT_(b)`C. `[(delP)/(delV_(M))]_(T_(c))=0`D. The compressibility factor at critical conditions is `8//3` |
| Answer» `(RT_(c))/(P_(c)V_(c)) = (8)/(3), :. Z = (P_(c)V_(c))/(RT_(c)) = (3)/(8)` | |
| 53. |
Which one of the following statements is wrong for gasesA. Gases do not have a definite shape and volumneB. Volume of the gas is equal to the volume of the container confining the gasC. Confined gas exerts uniform pressure on the walls of its container in all directionsD. Mass of the gas cannot be determined by weighing a container in which it is enclosed |
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Answer» Correct Answer - D The mass of gas can be determined by weighing the container, filled with gas and again weighing this container after removing the gas. The difference beetween the two weights gives the mass of the gas. |
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| 54. |
Which of the following statements is not correct about the three states of matter, i.e., solid, liquids and gas?A. Molecules of a solid possess least energy whereas those of a gas possess highest energyB. The density of solid is highest whereas that of gases is lowestC. Gases like liquids possess definite volumesD. Molecules of a solid possess vibratory motion |
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Answer» Correct Answer - C Gases do not have definite shape and volume. Their volume is equal to the volume of the container. |
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| 55. |
Which of the following exhibits the weakest intermolecular forces?A. `NH_(3)`B. `HCl`C. `He`D. `H_(2)O` |
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Answer» Correct Answer - C Noble gas has no intermolecular forces due to inertness. |
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| 56. |
A small capillry tube of length 100cm closed at one end is kept horizontally and a mercury column of length 10cm is exactly in the middle. If the atmospheric pressure is 1 atm then identify the correct option(s).A. The pressure of "air trapped" in the orgina: horizontal position is 750mm of Hg.B. The length of the air trapped when the tube is held vertically with open end upwards is `(45xx76)/(86)cm`.C. The length of the air trapped when the tube is held vertically with open end downwards is `(45xx76)/(66)cm`.D. No air will be trapped when it is held vertically with open end downward. |
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Answer» Correct Answer - b,c |
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| 57. |
If the difference in the level of Hg in an open arm manometer (One end open to atmosphere and other end is connected to gas chamber) is 6 mm. then what can be the pressure of gas? (Given: 1 atm=1.01325xx `10^(5)N//m^(2)`)A. 765mm of HgB. 755 mm of HgC. 765 torrD. 700torr |
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Answer» Correct Answer - abc |
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| 58. |
Which of the following relations for expressing volume of a sample is not correctA. `1L = 10^(3) ml`B. `1 dm^(3) = 1 L `C. ` 1L = 10^(3) m^(3)`D. ` 1L = 10^(3) cm^(3)` |
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Answer» Correct Answer - C `1L =10^(-3)m^(3)=10^(3)cm^(3)=1dm^(3)=10^(3)ml` |
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| 59. |
Two closed vessels of equal volume containing air at pressure `P_(1)` and temperature `T_(1)` are connected to each other through a narrow tube. If the temperature in one of the vessels is now maintained at `T_(1)` and that in the other at `T_(2)`, what will be the pressure in the vessels?A. `(T_(1))/(2P_(1)T_(2))`B. `(2P_(1)T_(2))/(T_(1)+T_(2))`C. `(2P_(1)T_(2))/(T_(1)-T_(2))`D. `(2P_(1))/(T_(1)+T_(2))` |
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Answer» Correct Answer - b (b) Let `T_(1)gtT_(2)`, final pressure will be same, Let x mole transfer from A to B vessel. `:." " P_(A)V=(n-x)RT` and `P_(A)V=(n+x)RT_(2)` `:." " x=(n(T_(1)-T_(2)))/(T_(1)+T_(2)),` `"finally "P_(1)xx2V=2nRT_(1),V=(nRT_(1))/(P_(1))` `:." " P_(A)xx(nRT_(1))/(P_(1))=(n-(n(T_(1)-T_(2)))/((T_(1)+T_(2))))RT_(1)` `P_(A)=(2P_(1)T_(2))/(T_(1)+T_(2))` |
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| 60. |
Two containers are connected by a tube of negligible volume container (I) has `N_(2)(g)` gas at a pressure 4 atm and temperature T (K) and container (II) has 1 litre `H_(2)O(l)` at temp (T) initially. Find correct option(s) after stopcock is removed. (Aq. tension=190torr) A. Pressure of `N_(2)=2.0` atmB. Total pressure=2.25atmC. Total pressure=1.05 atmD. Pressure of `H_(2)O(g)` is 0.25 atm |
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Answer» Correct Answer - abd |
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| 61. |
If same amount of gas is trapped over liquid (a) and liquid (b) in following containers. Assuming temperature and cross-sectional area of container are same. `P_(atm)=760mm Hg,d_(Hg)=13.6 g//mL` Find the pressure (in cm Hg) of gas over the liquid (b). A. 76 cmB. 11 cmC. 50 cmD. 65 cm |
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Answer» Correct Answer - c |
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| 62. |
If same amount of gas is trapped over liquid (a) and liquid (b) in following containers. Assuming temperature and cross-sectional area of container are same. `P_(atm)=760mm Hg,d_(Hg)=13.6 g//mL` The density of liquid (b) will be: A. `5g//cc`B. `10 g//cc`C. `15 g//cc`D. `20 g//cc` |
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Answer» Correct Answer - b |
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| 63. |
If distance between 2 molecuels is r then lim `(1)/(r^(x))` will result in which of the following equations to be true/applicable?A. Z=1B. `Zlt1`C. `Zgt1`D. `PV_(m)=RT` |
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Answer» Correct Answer - ad |
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| 64. |
To expel half the mass of air from a large flask at `27^(@)C` it must be heated to .A. `54^(@)C`B. `177^(@)C`C. `277^(@)C`D. `327^(@)C` |
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Answer» `PV =nRT ` at constant `P` and `V` `n_(1) T_(1) =n_(2) T_(2)` `n_(1) xx 300 = (n_(1))/(2) xx T` `:. T = 600 K =327^(@)C` . |
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| 65. |
Using the van der Waals equation, calculate the pressure of `10.0mol NH_(3)` gas in a `10.0 L` vessel at `27^(@)C`. `{:((P+n^(2)(a)/(V^(2)))(V-nb)=nRT,,a=4.2L^(2).atm//mol^(2),,b=0.037L//mol):}` |
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Answer» Correct Answer - `21.37atm`. `(P+(n^(2)+4.2)/((10)^(2)) (V-nb) =nRT` `(P+((10)^(2)xx4.2)/((10)^(2))) (10-10 xx 0.037) = 10 xx 0.082 xx 300` |
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| 66. |
Statement-1: Critical temperature of the gas is the temperature at which it occupies 22.7L of volume. Statement-2: Molar volume of every gas at STP is 22.7L.A. Statement-I is True, Statement-II is True : Statement-II is a correct explanation for Statement-IB. Statement-I is True, Statement-II is True : Statement-II is `NOT` a correct explanation for Statement-IC. Statement-I is True, Statement-II is False.D. Statement-I is False, Statement-II is True. |
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Answer» Correct Answer - c |
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| 67. |
Statement-1: Excluded volume or co-volume equals to (V-nb) for n moles gas. Statement-2: co-volume depends on the effective size of gas molecules.A. Statement-I is True, Statement-II is True : Statement-II is a correct explanation for Statement-IB. Statement-I is True, Statement-II is True : Statement-II is `NOT` a correct explanation for Statement-IC. Statement-I is True, Statement-II is False.D. Statement-I is False, Statement-II is True. |
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Answer» Correct Answer - d |
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| 68. |
`H_(2) and O_(2)` are kept in mass ratio `1:8` respectively at 6 atm. If small orifice is made then relative rate of effusion of `H_(2)` with respect to `O_(2)` initially is : |
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Answer» Correct Answer - 8 |
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| 69. |
Calculate the mole present of `N_(2)` gas in a mixture of `N_(2) and O_(2)` if the partial pressure of `O_(2)` is `6.3` cm of Hg in a container of volume `22.4` litre and total pressure is `90` cm of Hg at `300 K` |
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Answer» Correct Answer - 93 |
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| 70. |
Calulate the mole fraction of `N_(2)` gas in a mixture of `N_(2) and O_(2)`. If the partial pressure of `O_(2)` is 63 of Hg and the total pressure of the mixture is 90 cm of Hg. First multiply your answer with 10, then fill OMR. |
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Answer» Correct Answer - 3 |
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| 71. |
`3.7 gm` of gas at `25^(@)C` occupied the same volume as `0.184 gm` of hydrogen at `17^(@)C ` and at the same pressure. What is the molecular mass of the gas ?A. `82.66`B. 41.33C. 20.67D. 10.33 |
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Answer» Correct Answer - 2 For hydrogen we known that `PV=(w)/(M)RT=(0.184)/(2)xxRxx290` For unknown gas `PV=(3.7)/(M)xxRxx298` Equating both the equation `(3.7)/(M)xxRxx298=(0.184)/(2)xxRxx290` `M=41.33` |
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| 72. |
In a mixture of `N_(2)` and `O_(2)` gases, the mole fraction of `N_(2)` is found to be 0.700. the total pressure of the mixture is 1.42atm. What is the partial pressure of `O_(2)` in the mixture?A. 0.211atmB. 0.426atmC. 0.493atmD. 0.994atm |
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Answer» Correct Answer - b |
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| 73. |
`180ml` of hydrogen diffuses through a porous membrane in 15 minutes while `120 ml` of `SO_(2)` under identical conditions diffused in 20 minutes. What is the molecular mass of the hydrocarbon ?A. 8B. 16C. 24D. 32 |
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Answer» Correct Answer - 2 `(r_(1))/(r_(2))=sqrt((M_(SO_(2)))/(M_("hydrocarbon")))(180//15)/(120//20)=sqrt((64)/(M))` `2=sqrt((64)/(M))=M=16` |
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| 74. |
The molecular weight of a gas which diffuses through a porous plug at `1//6^(th)` of the speed of hydrogen under identical condition is:A. 27B. 72C. 36D. 48 |
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Answer» Correct Answer - b (b) `(r_(1))/(r_(H_(2)))=sqrt((2)/(M_(1)))=(1)/(6)` `M=72` |
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| 75. |
Two bulbs of volumes 200 `cm^(3)` and 100 `cm^(3)` are connected by a short tube containing an insulating porous plug that permits equalization of pressure but not of temperature between the bulbs. The system is sealed at `77^(@)C` when it contains oxygen under a pressure of 1 bar. The small bulb is immersed at `27^(@)C` and the large bulb is placed at `127^(@)C`. Neglecting thermal expansion of the bulbs, select the correct options.A. Final pressure inside the system would be greater than 1 barB. Final pressure inside the system would be less than 1 barC. Number of moles of `O_(2)` would increase in small container compared to initialD. Number of moles of `O_(2)` would increase in big container compared to initial |
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Answer» Correct Answer - ac |
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| 76. |
A certain volume of argon gas (Mol. Wt.=40) requires 45s to effuse through a hole at a certain pressure and temperature. The same volume of another gas of unknown molecular weight requires 60s to pass through the same hole under the same conditions of temperature and pressure. The molecular weight of the gas is:A. 53B. 35C. 71D. 120 |
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Answer» Correct Answer - c |
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| 77. |
Which of the following pairs will effuse at the same rate through a porous plug .A. `CO,NO_(2)`B. `NO_(2),CO_(2)`C. `NH_(3),PH_(3)`D. `NO,C_(2)H_(6)` |
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Answer» Correct Answer - D Because both NO and `C_(2)H_(6)` have same molecular weights `[M_(NO)=M_(C_(2)H_(6))30]` and rate of diffusion `prop(1)/(sqrt("molecular weight"))` |
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| 78. |
The density of vapour of a substance `(X)` at 1 atm pressure and 500 K is `0.8 kg//m^(3)`. The vapour effuse through a small hole at a rate of `4//5` times slower than oxygen under the same condition. What is the compressibility factor `(z)` of the vapour ?A. `0.974`B. `1.35`C. `1.52`D. `1.22` |
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Answer» Correct Answer - C `(r_(X))/(r_(O_(2)))=sqrt((MO_(2))/(M_(x)))=((4)/(5))^(2)=(32)/(M_(x))` `M_(x)=50` `d_(x)=0.80kg//m^(3)` `V_(m)=(1000)/(800)xx50=62.5L` `Z=(PV_(m))/(RT)=(1xx62.5)/(0.0821xx500)=1.52` |
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| 79. |
If 4 g `O_(2)` effuse through a very narrow hole , How much `H_(2)` would have effused under identical conditions .A. 16gB. 1 gC. `1//4`gD. 64g |
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Answer» Correct Answer - B `(n_(o))/(n_(H))=sqrt((M_(H))/(M_(a)))implies (4//32)/(W_(H)//2)=sqrt((2)/(32))` `(4)/(32)xx(2)/(W_(H))=(1)/(4)implies W_(H)=1 gm` |
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| 80. |
A vessel of uniform cross-section of length 500 cm as shown in figure is divided in two parts by a weightless and frictionless piston one part contains 5 moles of He(g) and other part 2 moles of `H_(2)(g)` and 4 moles of `O_(2)(g)` added at the same temperature and pressure in which reaction takes place finally vessel cooled to 300 K and 1 atm. What is the length of He compartment? (Assume volume of piston and vol. of `H_(2)O(l)` formed are negligible) A. 187.5 cmB. 300 cmC. 312.5 cmD. none of these |
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Answer» Correct Answer - c (c) Moles of `O_(2)` remaining after reaction=4 - 1 = 3 `V prop n` is due to same T and P in each compartment after reaction. `:.` Length of He compartment `(5)/(5+3)xx500=312.5cm` |
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| 81. |
The density of vapour of a substance `(X)` at 1 atm pressure and 500 K is `0.8 kg//m^(3)`. The vapour effuse through a small hole at a rate of `4//5` times slower than oxygen under the same condition. What is the compressibility factor `(z)` of the vapour ?A. 0.974B. 1.35C. 1.52D. 1.22 |
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Answer» Correct Answer - c (c) `(r_(x))/(r_(O_(2)))=sqrt(M_(O_(2))/(M_(x)))=((4)/(5))^(2)=(32)/(M_(x))=M_(x)=50` `d_(x)=0.80kg//m^(3),` `V_(m)=(1000)/(800)xx50=62.5L` `Z=(PV_(m))/(RT)=(1xx62.5)/(0.0821xx500)=1.52` |
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| 82. |
The critical temperature of `O_(2)` and `N_(2)` are `155K` and ` 126 K` respectively Calculate the ratio of reduced temperature of `O_(2)` and `N_(2)` at `300 K` .A. Fewer electron than `O_(2)`B. Two covalent bondsC. V-shape structureD. Dipole momnet |
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Answer» The dipole moment in molecule results in strong intermolecular forces and since `T_(C) = (2a)/(27Rb) , T_(c)` is more for `H_(2)O` . |
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| 83. |
The critical density of the gas `CO_(2)` is `0.44 g cm^(-3)` at a certain temperature. If r is the radius of the molecules, `r^(3)` in `cm^(3)` is approximately. `(N` is Avogadro number)A. `(25)/(piN)`B. `(100)/(piN)`C. `(6)/(piN)`D. `(25)/(4Npi)` |
| Answer» Correct Answer - C | |
| 84. |
The critical temperature of water is higher than that of `O_(2)` because the `H_(2)O` molecule hasA. Fewer electrons than `O_(2)`B. two covalent bondsC. V-shapeD. dipole moment |
| Answer» Correct Answer - D | |
| 85. |
Which of the following is correct for critical temperature ?A. It is the highest temperature at which liquid and vapour can coexistB. Boyond this temperature, there is no distinction between the two phases and a gas cannot be liquefied by compression.C. At this temperature, the gas the liquid phases have different critical densitiesD. All are correct |
| Answer» Correct Answer - a,b | |
| 86. |
Which of the following is correct for critical temperatureA. It is the highest temperature at which liquid and vapour can coexistB. Beyond the critical temperature, there is no distinction between the two phases and a gas cannot be liquefied by compressionC. At critical temperature `(T _(c ))` the surface tension of the system is zeroD. At critical temperature the gas and the liquid phases have different critical densities. |
| Answer» Correct Answer - A::B::C | |
| 87. |
Which of the following is correct for critical temperature ?A. At is the highest temperature at which liquid and vapour can coexistB. Beyond this temperature the gas and the liquid phases have different critical densitiesC. At this temperature, the gas and the liquid phases have different critical densitiesD. |
| Answer» Correct Answer - A::B | |
| 88. |
The gas with the highest critical temperature isA. `H_(2)`B. HeC. `N_(2)`D. `CO_(2)` |
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Answer» Correct Answer - d `{:("Gas","Critical temperature"),(H_(2),33.2K),(He,5.3K),(N_(2),44.4K),(O_(2),154.5K),(CO_(2),304.2K):}` |
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| 89. |
Statement-1: Noble gases can be liquefied. Statement-2: Molecular mass of nitrogen is smaller than that of oxygen.A. Statement-I is True, Statement-II is True : Statement-II is a correct explanation for Statement-IB. Statement-I is True, Statement-II is True : Statement-II is `NOT` a correct explanation for Statement-IC. Statement-I is True, Statement-II is False.D. Statement-I is False, Statement-II is True. |
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Answer» Correct Answer - a |
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| 90. |
Ideal gas do not show Joule -Thoson effect as well as they cannot be liquefied `((deltaU)/(deltaV))_(T)and ((deltaT)/(deltaP))_(H)` for ideal gas is zero . |
| Answer» Internal energy of an ideal gas depends only on temperature and since they have on attractions among their molecules `((deltaT)/(deltaP))_(H)` is zero i.e `mu J.T =0` . | |
| 91. |
Compressibility factor for `H_(2)` behaving as real gas is:A. `1`B. `(1-(a)/(RTV))`C. `(1+(Pb)/(RT))`D. `(RTV)/((1-a))` |
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Answer» Correct Answer - C `PV = Pb +RT rArr (PV)/(RT) =1 +(Pb)/(RT)` |
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| 92. |
Adiabatic demagnetisation is atechnique used forA. Adiabatic expansion of a gasB. Production of low temperatureC. Production of high temperatureD. None |
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Answer» Correct Answer - B Adiabaic demagnetisation is a techanique of liquefaction of gases in which temperature is reduced. |
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| 93. |
`4.48 L` of an ideal gas at `STP` requires 12 cal to raise its temperature by `15^(@)C` at constant volume. The `C_(P)` of the gas isA. 3 calB. 4 calC. 7 calD. 6 cal |
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Answer» Correct Answer - D No. of moles of ideal gas at STP `= (4.48)/(22.4) =0.2` mol `Delta U = Delta nC_(V) Delta T , 12 = (4.48)/(22.4)xxC_(V)xx15, 12=0.2 xx C_(V)xx15` `:. C_(V)= 12//3 =4, C_(p)-C_(V)=R=2`, `:. C_(P)=2+C_(V)=2+4=6cal mol^(-1)` |
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| 94. |
A gas is liquefiedA. Above critical temperature and below cricical pressureB. Below critical temperature and above critical pressureC. Below critical temperature and pressureD. Above critical temperature and pressure |
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Answer» Correct Answer - C The temperature above which the gas cannot be liquefied is called the critical temperature and the minimum pressure required to liquefy the gas at the critical temperature is called the critical pressure. |
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| 95. |
`CH_(4)` gas is behaving non-ideally. Compressibility factor for gas is 1.5 at 2 atm, 400K. Calculate molar volume for gas: [Given: `R=0.08("Litre"-"atm")/(K-"mole")`]A. 24 litreB. 16 litreC. 48 litreD. 8 litre |
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Answer» Correct Answer - a |
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| 96. |
An unknown gas behaves ideally at 540 K in low pressure region, then calculate the temperature (in K) below which it can be liquefied by applying pressure. |
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Answer» Correct Answer - 160 |
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| 97. |
A bulb of three litre capacity filled with air is heated from `27^(@)C` The air thus expelled measured `1.45` litre at `17^(@)C` Considering the pressureto be 1 atm throughout the experiment and ignoring the expansion of calculate t . |
| Answer» Correct Answer - `327^(@)C` | |
| 98. |
There are three closed containers in which equal moles of gas is filled if the containers are placed at the same temperature, then which of the following is correct?A. Pressure in I is the maximum.B. Pressure in II is the maximum.C. Pressure in III is the maximum.D. All in III is the maximum. |
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Answer» Correct Answer - a |
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| 99. |
One litre of a gas weights 2 g at 300 K and 1 atm pressure. If the pressure is made 0.75 atm at which of the following temperature will one litre of the same gas weight one gram ?A. 450KB. 600KC. 800 KD. 900 K |
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Answer» Correct Answer - A `(P_(1)V_(1))/(n_(1)T_(1))=(P_(2)V_(2))/(n_(2)T_(2)):. T_(2)=(P_(2))/(P_(1))(V_(2))/(V_(1))T_(1) (m_(1))/(m_(2))=(0.75)/(1) xx (1)/(2) xx (2)/(1) xx 300K = 450 K` |
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| 100. |
A and B are ideal gases. The molecular weights of A and B are in the ratio of `1 : 4`. The pressure of a gas mixture containing equal weights of A and B is P atm. What is the partial pressure (in atm.) of B in the mixtureA. `(P)/(5)`B. `(P)/(2)`C. `(P)/(2.5)`D. `(3P)/(4)` |
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Answer» Correct Answer - A `M_(a)=a` and `M_(B)=4a` `w_(A) = w_(B)=m(`say) `x_(B)=(m//4a)/(4//ma+m//a)=(1)/(5)` |
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