**1.Which among the following will show anisotropy?**

(a) glass

(b) Barium chloride

(c) Wood

(d) Paper

**2.If a gas is expanded at constant temperature**

(a) the pressure increases

(b) the kinetic energy of the molecules remains the same

(c) the kinetic energy of the molecules decreases

(d) the number of molecules of the gas increases

**3.Vander waal constant ‘a’ has maximum value for ______**

(a) H_{2}

(b) He

(c) N_{2}

(d) SO_{2}

**4.Pressure cooker is used for cooking food on hills. The gas law involved in this process is **

(a) Boyle’s law

(b) Law Charles

(c) Avogadro’s law

(d) Gay-Lussac law

**5.Which gas occupies least volume in same time under same conditions ?**

(a) H_{2}

(B) Cl_{2}

(c) SO_{2}

(d) N_{2}

**6.Which set of conditions represent the easiest way to cool a gas ?**

(a) Low temperature and high pressure

(b) High temperature and low pressure

(c) Low temperature and low pressure

(d) High temperature and high pressure

**7.The constant ‘a’ is a maximum in van der Waal’s equation for**

(a) Helium

(b) Hydrogen

(c) Oxygen

(d) Ammonia

**8.A gas behaves most like an ideal gas under conditions of**

(a) High pressure and low temperature

(b) High temperature and high pressure

(c) Low pressure and high temperature

(d) Low pressure and low temperature

**9.The temperature at which real gases obey the ideal gas laws over a wide range of pressure is called**

(a) Critical temperature

(b) Boyle temperature

(c) Inversion temperature

(d) Reduced temperature

**10.Which is not true in case of an ideal gas?**

(a) It cannot be converted into a liquid

(b) There is no interaction between the molecules

(c) All molecules of the gas move with same speed

(d) At a given temperature, PV is proportional to the amount of the gas

**11.The temperature at which a real gas obeys ideal gas law over an appreciable range of pressure is called **

(a) Critical temperature

(b) Standard temperature

(c) Inversion temperature

(d) Boyle point

**12.Vander waal’s constant ‘a’ represents _____**

(a) Size of gas molecules

(b) Kinetic energy

(c) Intermolecular forces of attractions

(d) Collision frequency.

**13.Gases deviate from the ideal gas behaviour because their molecules**

(a) possess negligible volume

(b) have forces of attraction between them

(b) are polyatomic

(c) are not attracted to one another

**14.Equal weights of ethane and hydrogen are mixed in an empty container at 25C. The fraction of the total pressure exerted by hydrogen is**

(a) 1 : 2

(b) 1 : 1

(c) 1 : 16

(d) 15 : 16

**15.Which gas may have highest critical temperature ?**

(a) He

(b) H_{2}

(c) O_{2}

(d) NH_{3}

**16.Which is correct statement **

(a) Surface tension decreases as the temperature is raised

(b) Lesser the viscosity, the more slowly the liquid focus

(c) Viscosity of liquids increases a the temperature rises

(d) SI unit of viscosity coefficient is poise

**17.If a gas expands at constant temperature, select correct statement**

** (1) the pressure decreases**

** (2) the kinetic energy of the molecules remains the same**

** (3) the K.E. of the molecules decreases**

** (4) the number of molecules of the gas increase.**

(a) 1, 2

(b) 1, 2, 3

(c) 1, 2, 4

(d) 2, 3

**18.In a gas intermolecular forces are negligible, At what pressure the gas occupies double the volume than expected ? (b = vander waal’s constant) **

(a) b/RT

(b)RT/b

(c) RTb

(d) RT

**19.Which of the following quantities is the same for all ideal gases at the same temperature?**

(a) The kinetic energy of 1 mol

(b) The kinetic energy of 1g

(c) The number of molecules in 1 mol

(d) The number of molecules in 1 g

**20.The compressibility of a gas is less than unity at STP. Therefore**

(a) V_{m} > 22.4 litres

(b) V_{m} < 22.4 litres

(c) V_{m} = 22.4 litres

(d) V_{m} = 44.8 litres

**21.Which of the following sample has maximum r.m.s. velocity ?**

(a) at 27°C

(b) at 27°C

(c) at 127°C

(d) He at 127°C

**22.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

**23.Which gas is least compressible ?**

(a) at 800 atm

(b) at 200 atm

(c) at 1 atm

(d) at 10 atm

**24.A liquid is in equilibrium with its vapour at it’s boiling point. On the average, the molecules in the two phases have equal:**

(a) inter-molecular forces

(b) potential energy

(c) kinetic energy

(d) total energy

**25.Rate of diffusion of a gas is:**

(a) directly proportional to its density

(b) directly proportional to its molecular weight

(c) directly proportional to the square root of its molecular weight

(d) inversely proportional to the square root of its molecular weight

**26.For an ideal gas, number of moles per litre in terms of its pressure P, gas constant R and temperature T is**

(a) PT/R

(b) PRT

(c) P/RT

(d) RT/P

**27.10 grams each of and He are present in a flask at 27°C. What is the ratio of the average kinetic energy of the Indivisual gases ?**

(a) 1 : 1

(b) 2 : 1

(c) 5 : 1

(d) 5 : 3

**28.When an ideal gas undergoes unrestrained expansion, no cooling occurs because the molecules:**

(a) are above the inversion temperature

(b) exert no attractive forces on each other

(c) do work equal to loss in kinetic energy

(d) collide without loss of energy

**29.A sample of O _{2} gas is collected over water at 23ºC at a barometric pressure of 751 mm Hg (vapour pressure of water at 23ºC is 21 mm Hg). The partial pressure of O_{2} gas in the sample collected is**

(a) 21 mm Hg

(b) 751 mm Hg

(c) 0.96 atm

(d) 1.02 atm

**30.Rate of diffusion of a gas is**

(a) directly proportional to its density

(b) directly proportional to its molecular weight

(c) directly proportional to the square root of its molecular weight

(d) inversely proportional to the square root of its molecular weight

**31.The vanderwaal’s constant ‘a’ for the gases CO,, NO and are 1.49, 0.024, 1.34 and 0.034 respectively. The gas which shows highest critical temperature is**

(a) CO

(b) H_{2}

(c) NO

(d) He

**32.The values of van der Waals constant ‘a’ for the gases O _{2}, N_{2}, NH_{3} and CH_{4} are 1.360, 1.390, 4.170 and 2.253 L^{2} atm mol^{–2} respectively. The gas which can most easily be liquefied is**

(a) O_{2}

(b) N_{2}

(c) NH_{3}

(d) CH_{4}

**33.The ratio of the partial pressure of a gaseous component to the total vapour pressues of the mixture is equal to**

(a) mass of the component

(b) mole fraction of component

(c) mass percent of the component

(d) molecular mass of the component

**34.Positive deviation from ideal behavior takes place because of**

(a) Molecular interaction between atoms and PV/nRT > 1

(b) Molecular interaction between atoms and PV/nRT < 1

(c) Finite size of atoms and PV/nRT > 1

(d) Finite size of atoms and PV/nRT < 1

**35.The root mean square speeds at STP for the gases H, N, Oand HBr are in the order:**

(a) H< N< O< HBr

(b) HBr < O< N < H

(c) H < N = O < HBr

(d) HBr < O< H < N

**36.The volume of a gas is 100 mL at 100 **^{O}**C. If pressure remains constant then at what temperature it will be 200 mL?**

(a) 200 ^{O}C

(b) 473 ^{O}C

(c) 746 ^{O}C

(d) 50 ^{O}**C**

**37.Air contains 79% N _{2} and 21% O_{2} by volume. If the barometric pressure is 750 mm Hg, the partial pressure of oxygen is**

(a) 157.5 mm of Hg

(b) 175.5 mm of Hg

(c) 3125.0 mm of Hg

(d) None of these

**38.A gas is found to have a density of 1.80 g L ^{-1} at 760 mm pressure and 27ºC. The gas will be**

(a) O_{2}

(b) CO_{2 }

(c) NH_{3}

(d) SO_{2}

**39.In a closest packed lattice, the number of tetrahedral voids formed will be**

(a) Equal to the number of spheres in the lattice

(b) Half than that of the number of spheres

(c) Double than that of the number of spheres

(d) None of these

**4o. If pressure becomes double at the same absolute temperature on 2 L CO _{2}, then the volume of CO_{2} becomes**

(a) 2L

(b) 4L

(c) 5L

(d) 1L

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