Question

(i) In your own words, state Boltzmann's two principles of statistical mechanics. (ii) In the context of statistical mechanics, explain what is meant by a phase cell, and explain how such cells may be used in the specification of the configuration of a classical 4 marks) gas. (i) In your own words, state Boltamann's distribution law for a gas in equilibrium (ii) If the probability of any given molecule occupying any given phase cell is known, what additional information is required i orderto work out the equilibrium distribution of molecular speeds in a pure gas? (c) A sealed container of volume V-0.10 m3 holds a sample of N = 3.0 x 1024 atoms of helium gas in equilibrium. The distribution of speeds of the helium atoms shows a peak at 1.1 x 103 ms-1 (i) Caleulate the ternperature and pressure of the helium gas. (ii) What is the average kinetic energy of the helium atoms? (ii) What is the energy corresponding to the maximum in the energy (4 marks) distribution? (12 marks) (Take the mass of each helium atom to be 4.0amu.)

Answer 1

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