Molecular Physics | Thermodynamics Answers

Nitrogen gas having a mass of 0.8 kg at 110 kPa and 50℃ is contained in a cylinder. The piston is moved compressing nitrogen until the pressure becomes 1.1 MPa and temperature becomes 200℃. The work done during the process is 50 kJ. Find the heat transferred from the nitrogen to the surroundings. Use 𝑐𝑣 for nitrogen = 0.75 kJ/kg-K.

A system has N distinguishable particles. Each particle has two non-degenerate states 

with level separation of 0.15 eV. Calculate the average number of the particles in each 

state when the system is in thermal equilibrium with the bath temperature of 300 K.

(3)

Explain entropy

Derive Planck’s law of black body radiation.

In a pipe that has a cross-sectional area of 0.5 m^2 and a flow rate of 1.5 m^3/s, what is the average speed of the fluid carried by the pipe? *

A man eats 3500 calories of food. How much work can he perform?

How much heat is required to change 200ml of ice at - 22°C into steam 100 °C

c)

For a given gas the coefficient of viscosity is 1.9 x 10 Nsm and the diffusion

coefficient is 1.2 x 10-5 m?s-. Calculate the density and mean free path at average

molecular velocity of 380 ms-1

 A rectangular block of metal of mass 1500kg is 2m high and stands on a square base of side 0.5m.What is the area base?

1. Ammonia is polar molecule while boron trifluoride is a non polar molecule. Explain the difference in the polarity of these co pounds.

2. Suppose that AB3E a hypothetical moleculeis discovered . Predict whether the molecule is polar or nonpolar by determining its molecular shape.

Note : A- corresponds to central atom

B- Terminal atom

E-lone pair ( nonbonding electrons)