Chapter 6, Problem 6.67P

A certain ideal gas has a constant R = 38.9 ft-lff/lbm-R with k = 1.4. a) If 3 lbm of this gas undergoes a reversible nonflow constant volume process from 120 psia,740 oF to 140 oF find P2, ∆U, ∆H, Q, Work. b) If the process in “a” had been steady flow find work and ∆S.

4.7 The refrigerant R-22 is contained in a piston/cylinder as shown in Fig. P4.7, where the volume is 11 L when the piston hits the stops. The initial state is -30°C, 150 kPa with a volume of 10 L. This system is brought indoors and warms up to 15°C. a. Is the piston at the stops in the final state? b. Find the work done by the R-22 during this process.

Two rigid tanks are filled with water. Tank A is 0.2 m³ at 100 kPa, 150°C and tank B is 0.3 m³ at saturated vapor 300 kPa. The tanks are connected by a pipe with a closed valve. We open the valve and let all the water come to a single uniform state while we transfer enough heat to have a final pressure of 300 kPa. Give the two property values that determine the final state and find the heat transfer. B A

Two vessels A and B of different sizes are connected by a pipe with a valve. Vessel A contains 140 L of air at 3000kPa, 90oC. Vessel B, of unknown volume, contains air at 70 kPa, 5oC. The valve is opened and, when the propertieshave been determined, it is found that pm = 1400 kPa, tm = 45oC. (a) What is the mass in kg of air initially inside vessel A (b) What is the volume of vessel B in liters?

(b) Steam at 140 bar has an enthalpy of 3001.9 kJ/kg, find the temperature, specific volume and the internal energy.

A piston cylinder has 2.2 kg of air at 300 K and 150 kPa. It is now heated up in a two step process. First constant volume to 1000 K (state 2) then followed by a constant pressure process to 1500 K, state 3. Find the final volume and final pressure.   (R of air = 0.287 KJ/kg K)

1.Five kilogram of steam is initially at 1MPa and y=40% inside the piston cylinder. There is a 50C superheat introduced in steam isopiestically. Find the change of entropy of the steam.

4.27 A 400-L tank, A (see Fig. P4.27) contains argon gas at 250 kPa, 30°C. Cylinder B, having a frictionless piston of such mass that a pressure of 150 kPa will float it, is initially empty. The valve is opened and argon flows into B and eventually reaches a uniform state of 150 kPa, 30°C throughout. What is the work done by the argon? Po 8 Argon A FIGURE P4.27 B

6. Five pounds of a certain ideal gas with K 1.30 and R= 35 is compressed in %3D polytropic process in a closed system from 15 psia, 80 F to 60psia, 315 F. Compute the polytropic index n, the work nonflow and the heat interactions with the surroundings