Molecular Physics | Thermodynamics Answers

A poorly ventilated commercial kitchen contains 120 kg of air at a temperature of 19°C and and with a relative humidity of 30% at the start of the evening shift.

At the end of the shift the temperature in the kitchen is 28°C and water is condensing on the walls and ceilings.

What is the minimum amount of water vapour that has been added to the air in the kitchen over the course of the shift? (to 2 s.f and in kg)

What is Gibb's paradox ? Why does it arise ?
Obtain Sackur-Tetrode equation and show that it is free from Gibb's paradox.

Using Maxwell relations, derive 1st and 2nd
energy equations. Discuss their physical
significance.

What is Joule-Thomson effect ? Obtain the
expression for Joule-Thomson coefficient for an Ideal gas.

The pressure exerted by an ideal gas is given
by
p = 1/3 mnv²
Using this expression deduce Avogadro's
law.

Define mean free path. Assuming that the
collision probability is a function of distance,
obtain the Survival Equation.

Discuss the significance of Brownian motion in kinetic theory of gases. Obtain the expression for particle concentration in sedimentation process. The motion of soot particles of radius 0.5 x 10^-4 cm in water-glycerine solution characterized by n= 2.80 x 10^-3 kg m^-1 s^-1 at 300 K was observed
for 10 s. The observed value of ∆(x² ) was
3.30 x 10^-8 cm². Calculate Boltzmann
constant.

Calculate the mean free path of H2
molecules at 300 K. The diameter of H2
molecules is 3 Å and the number density is
3 x 10^25 m^-3

What is entropy ? Calculate the change in entropy of an ideal gas for an isothermal expansion.

State the operational ranges and limitations of platinum resistance thermometer and Fe-Constantan thermocouple.