Acylinder (200 cm in length and 50 cm2 in cross-sectional area) is fitted with the piston which is connected to a spring that obeys hooke's law witha 2x106 dynes/cm force constant. hooke's law states that the force exerted by a spring is linearly proportional to the spring elongation and acts in a different opposite to the elongation. the chamber containing the spring is evacuated, while the other chamber contains 0.1 moles of helium initally at 25 degrees celcius and 1 bar. the system is initally at equilibrium.
the helium chamber is heated slowly until the temperature reaches 200 degrees celcius. assuming that the piston is frictionless and has negligible mass and thermal conductivity and that helium can be treated as an ideal gas of constant heat capacity cp = 20.9 j/mol k,
(a) what is the pressure of the helium when temperature reaches 200 degrees celcius?
(b) how much heat is required?
(c) what is the entopy change of the gas, the surroundings and the universe for the process?