A stream of propane is throttled from 4.298 bar and 450 K to 0.22 bar. This process is irreversible due to frictional losses at the nozzle.
a. In words or equations, why are frictional losses irreversible?
b. What is the final temperature of propane (after throttling)? The constant-pressure heat capacity of propane is 92.7 J/mol/K. Clearly state any assumptions you need to make to solve this problem.