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Chapter 3, Examples 3–28 A 1.8-m3 rigid tank contains steam at 220oC. One-third of the volume is in the liquid phase and the rest is in the vapor form. Determine (a) the pressure of the steam, (b) the quality of the saturated mixture, and (c) the density of the mixture.

3–38 Three kilograms of water in a container have a pressure of 100 kPa and temperature of 150oC. What is the volume of this container?

3–39 Water is to be boiled at sea level in a 30-cm-diameter stainless steel pan placed on top of a 3-kW electric burner. If 60 percent of the heat generated by the burner is transferred to the water during boiling, determine the rate of evaporation of water (kg/s).

3–43 Water initially at 200 kPa and 300oC is contained in a piston-cylinder device fitted with stops. The water is allowed to cool at constant pressure until it exists as a saturated vapor and the piston rests on the stops. Then the water continues to cool until the pressure is 100 kPa. On the T-v diagrams sketch, with respect to the saturation lines, the process curves passing through both the initial, intermediate, and final states of the water. Label the T, P and v values for end states on the process curves. Find the overall change in internal energy between the initial and final states per unit mass of water? (kJ/kg)

3–51 A piston–cylinder device contains 0.005 m3 of liquid water and 0.9 m3 of water vapor in equilibrium at 600 kPa. Heat is transferred at constant pressure until the temperature reaches 200oC. determine (a) the initial temperature of the water? (b) The total mass of the water (c)The final volume (d) Show the process on a P-v diagram with respect to saturation lines.

3–60 [5th edition], A 0.3-m3 rigid vessel initially contains saturated liquid–vapor mixture of water at 150°C. The water is now heated until it reaches the critical state. Determine the mass of the liquid water and the volume occupied by the liquid at the initial state.

3–64 A piston–cylinder device initially contains 50 L of liquid water at 40°C and 200 kPa. Heat is transferred to the water at constant pressure until the entire liquid is vaporized. (a) What is the mass of the water? (b) What is the final temperature? (c) Determine the total enthalpy change. (d) Show the process on a T-v diagram with respect to saturation lines.

3–54 [5th edition] A 0.5-m3 vessel contains 10 kg of refrigerant-134a at -20°C. Determine (a) the pressure, (b) the total internal energy, and (c) the volume occupied by the liquid phase

Complete the following table, using thermodynamics tables of water

Temp “ 0C ”

Pressure “kPa”

300

h “kJ/kg”

v (m3/kg)

Quality Phase description x

2944.2 900

Saturated Liquid

155

0.1565

Solution

Temp “ 0C ”

Pressure “kPa”

h “kJ/kg”

v (m3/kg)

Quality Phase description x

300

4500

2944.2

0.05138

NA

Superheated

175.35

900

742.56

0.001121

0.0

Saturated Liquid

155

543.49

1597.9

0.1565

0.45

Two phase

3–75 A 1-m3 tank containing air at 10oC and 350 kPa is connected through a valve to another tank containing 3 kg of air at 35oC and 200 kPa. Now the valve is opened, and the entire system is allowed to reach thermal equilibrium with the surroundings, which are at 20oC. Determine the volume of the second tank and the final equilibrium pressure of air

3–76 A rigid tank whose volume is unknown is divided into two parts by a partition. One side of the tank contains an ideal gas at 927oC. The other side is evacuated and has a volume twice the size of the part containing the gas. The partition is now removed and the gas expands to fill the entire tank. Heat is now applied to the gas until the pressure equals the initial pressure. Determine the final temperature of the gas.

3–71 The pressure gage on a 2.5-m3 oxygen tank reads 500 kPa. Determine the amount of oxygen in the tank if the temperature is 28o C and the atmospheric pressure is 97 kPa.

3–109 [ 5th edition] A rigid tank contains an ideal gas at 300 kPa and 600 K. Now half of the gas is withdrawn from the tank and the gas is found at 100 kPa at the end of the process. Determine (a) the final temperature of the gas and (b) the final pressure if no mass was withdrawn from the tank and the same final temperature was reached at the end of the process.

3–41 10-kg of R-134a at 300 kPa fills a rigid container whose volume is 14 L. Determine the temperature and total enthalpy in the container. The container is now heated until the pressure is 600 kPa. Determine the temperature and total enthalpy when the heating is completed....