1. The volume of argon gas in a reciprocating cylinder is 0.2 m3, its pressure is 600 kPa, and its temperature is 320 K. Argon gas expands to a pressure of 300 kPa at constant temperature.

a ) Calculate the work done during the expansion. What happens to heat exchange?

b ) Calculate the work done and heat exchange if the expansion is based on reversible polytropic PV 1.85 = steady state change.

c ) Calculate the work done if the expansion is performed according to the reversible adiabatic process.

d ) Show the phase changes in a , b and c , constant temperature curves, constant pressure curves, work and heat exchanges in P-V and T-S diagrams. Compare the values of work and heat exchanges.

e ) Calculate the entropy changes in the processes a , b and c .

HOW TO SOLVE THIS QUESTIONS? ANSWERS BELOW

a) m = 1,802 kg , W_12a = 83,18 kJ ,

Q_12a = W_12a

b) W_12b = 38,47 kJ , Q_12b = -10,63 kJ ),

c) W_12c = 43,63 kJ , Q_12c =0) , d ) ΔS_12a = 0,2600 kJ/K

ΔS_12b = - 0,0386 kJ/K , ΔS_12c = 0 )