States of Matter Questions and Answers Part-8

1. A certain gas takes three times as long to effuse out as helium. Its molecular mass will be :
a) 27 u
b) 36 u
c) 64 u
d) 9 u

  Discussion

Answer: b
Explanation:
q71

2. Maximum deviation from ideal gas is expected from :
a) \[N_{2}\left(g\right)\]
b) \[CH_{4}\left(g\right)\]
c) \[NH_{3}\left(g\right)\]
d) \[H_{2}\left(g\right)\]

  Discussion

Answer: c
Explanation: Higher the critical temperature more easily will be the gas liquify. Now since most easily liquifiable gas show larger deviation, NH3 will show maximum deviation from ideal behaviour.

3. For an ideal gas, number of moles per litre in terms of its presure P, gas constant R and temperature T is
a) PT/R
b) PRT
c) P/RT
d) RT/P

  Discussion

Answer: c
Explanation: PV = nRT (number of moles = n/V)
n/V = P/RT

4. Value of gas constant R is
a) 0.082 litre atm
b) \[0.987 cal mol^{-}K^{-1}\]
c) \[8.3 J mol^{-}K^{-1}\]
d) \[83 erg mol^{-}K^{-1}\]

  Discussion

Answer: c
Explanation: \[8.3 J mol^{-}K^{-1}\]

5. Kinetic theory of gases proves
a) only Boyle’s law
b) only Charles’ law
c) only Avogadro’s law
d) All of these

  Discussion

Answer: d
Explanation: All of these

6. The heat required to raise the temperature of body by 1 K is called
a) specific heat
b) thermal capacity
c) water equivalent
d) none of these

  Discussion

Answer: b
Explanation: The heat rquired to raise the temperature of body by 1K is called thermal capacity or heat capacity.

7. What volume of hydrogen gas, at 273 K and 1 atm pressure will be consumed in obtaining 21.6 g of elemental boron (atomic mass = 10.8) from the reduction of boron trichloride by hydrogen ?
a) 67.2 L
b) 44.8 L
c) 22.4 L
d) 89.6 L

  Discussion

Answer: a
Explanation:
q77

8. According to the kinetic theory of gases, in an ideal gas, between two successive collisions a gas molecule travels
a) in a wavy path
b) in a straight line path
c) with an accelerated velocity
d) in a circular path

  Discussion

Answer: b
Explanation: According to kinetic theory the gas molecules travel in a straight line path but show zig-zag motion due to collisions.

9. As the temperature is raised from 20ºC to 40ºC, the average kinetic energy of neon atoms changes by a factor of which of the following ?
a) \[313\diagup293\]
b) \[\sqrt{\left(313\diagup293\right)}\]
c) \[1\diagup2\]
d) 2

  Discussion

Answer: a
Explanation:
q79

10. In van der Waals equation of state of the gas law, the constant ‘b’ is a measure of
a) volume occupied by the molecules
b) intermolecular attraction
c) intermolecular repulsions
d) intermolecular collisions per unit volume

  Discussion

Answer: a
Explanation: In van der waal's equation ‘b’ is for volume correction