Chapter 6, Problem 6.27P

One-tenth kmol of carbon monoxide (CO) in a piston- cylinder assembly undergoes a process from p1 = 150 kPa, T1 = 300 K to p2 = 500 kPa, T2 = 370 K. For the process, W = -300 kJ. Employing the ideal gas model, determine: (a) the heat transfer, in kJ. (b) the change in entropy, in kJ/K.

0.2 m³ of air at 4 bar and 130 °C is contained in a system. A reversible isothermally expansion takes place till the pressure falls to 1.02 bar. The gas is then heated at constant pressure till Temperature is 144 °C. Calculate: (i) Pressure, Temperature and volume of each state. (ii) The work done. (iii) The net heat supplied. Take cp = 1 kJ/kg K, cv = 0.714 kJ/kg K.

A cylinder that contains 0.068 kg of carbon dioxide (with molar mass 44 kg/kmol), occupying a volume of 0.027 m3 at 1 bar is compressed reversibly until the pressure is 5.27 bar. If the molar (universal) gas constant as 8.3145 kJ/kmol K, calculate the the work done on the C02 (in J) when the process is isothermal.

A 340 L tank contains steam, initially at 400°C, 3 bar. A valve is opened for 20 seconds and steam flows out of the tank at a constant mass flow rate of 0.005 kg/s. During steam removal, a heater maintains the temperature within the tank constant. Determine final mass remaining in the tank, in kg, and the final pressure in the tank, in bar. Step 1 Determine final mass remaining in the tank, in kg. m₂ = 0.2297 kg Step 2 Determine the final pressure in the tank, in bar. P2= 2.111 x bar

Water contained in a closed, rigid tank, initially at 100 lbf/in2, 800oF, is cooled to a final state where the pressure is 25 lbf/in2.Determine the quality at the final state and the change in specific entropy, in Btu/lb·oR, for the process.

Thermodynamics

Argon (molar mass 40 kg/kmol) compresses reversibly in an adiabatic system from 5 bar, 25 0C to a volume of 0.2 m3. If the initial volume occupied was 0.9 m3, calculate the work input in MJ to 3 decimal places. Assume nitrogen to be a perfect gas and take cv = 0.3122 k J / k g K.

A divider separates 1 lb mass of carbon monoxide (CO) from a thermal reservoir at 150o F. the carbon monoxide, initially at 60o F  and 150 lbf/in2, expands isothermally to a final pressure of 10 lbf/in2 while receiving heat transfer through the divider from the reservoir. The carbon monoxide can be modeled as an ideal gas. (a) For the carbon monoxide as the system, evaluate the work and heat transfer, each in Btu and the amount of entropy produced, in Btu/oR. (b) Evaluate the entropy production, in Btu/oR, for an enlarged system that includesthe carbon monoxide and the divider, assuming the state of the divider remains unchanged. Compare with the entropy production of part (a) and comment on the difference.

Refrigerant 22 undergoes a constant-pressure process within a piston–cylinder assembly from saturated vapor at 5.0 bar to a final temperature of 30°C. Kinetic and potential energy effects are negligible.Evaluate the work and the heat transfer, each in kJ per kg of refrigerant.