Q4 A: Choose the correct answer of the following:
l-A saturation state is a state from which a change of phase may occur:
a) without a change of pressure or temperature
b) with a change of pressure or temperature
c) both of the mentioned
d) none of the mentioned
2- In an isothermal process:
a) the internal energy changes with pressure and temperature
b) the work is equal to the heat energy
c) the work is equal to enthalpy
d) the internal energy is equal to work
B) Ethylene liquid is stored in a 0.5m3 vessel at its vapor pressure and at a temperature of 243K. The liquid occupies only 70% of the vessel volume. Estimate the mass of the liquid. The vapor pressure of ethylene at 243K is 40bar.