Task $5$ Closed Tank with Propane

A rigid, closed tank $($a solid tank that does not change volume$)$ contains $3\mathrm{.}5$ kg of propane as superheated gas at a temperature of $50\backslash$deg C and a pressure of $4\mathrm{.}0$ bar. The contents of the tank are cooled down to the dew point $($where the first liquid droplets condense$).$ Changes in kinetic and potential energy can be assumed negligible.

a$)$ What is the temperature in the tank after cooling?

b$)$ What is the pressure in the tank after cooling?

c$)$ What is the change in the system's internal energy?

d$)$ How much heat has been released from the system to the surroundings?