Tag: gases and the kinetic theory

Questions Related to gases and the kinetic theory

A barometer reads 75 cm of mercury. When 2.0cm$^{3}$ of air at atmospheric pressure is introduced into space above the mercury level, the volume of the space becomes 50cm$^{3}$. The length by which the mercury column descends is

physics the kinetic model of matter gases and the kinetic theory concept of ideal gas and state equation of ideal gas behaviour of perfect gas and kinetic theory of gases

  1. 3 cm of Hg

  2. 6 cm of Hg

  3. 30 cm of Hg

  4. 10 cm of Hg

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Correct Option: A
Explanation:

Let the new pressure inside be $P$ after air introduced.

For the air,
$P _1V _1=P _2V _2$
$\implies P(50)=(75)(2)$
$\implies P=3\ cm\  of\ Hg$

Boyle's law is applicable when

a) temperature is constant

b) gas is at high temperature and low pressure

c) the vessel enclosing the gas is good conductor

d) the process is isothermal

physics the kinetic model of matter gases and the kinetic theory concept of ideal gas and state equation of ideal gas behaviour of perfect gas and kinetic theory of gases

  1. a & b

  2. b,c & d

  3. a,b & c

  4. a,b,c & d

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Correct Option: D
Explanation:

(a) Temperature must be constant to apply boyle's law
(b)From vanderwaal's equation when non idealities of a gas is undertaken then we can apply boyle's only when temperture is high and pressure is low
(c)Vessel enclosing must be a good conductor so there is no any possibilities of adiabatic process
(d) Temperature must be constant therefore, process must be isothermal
Hence all are correct
Hence option(D)