3-134 A 300-m3 rigid tank is filled with saturated liquid-
vapor mixture of water at 200 kPa. If 25 percent of the mass
is liquid and 75 percent of the mass is vapor, the total mass
in the tank is
(a) 451 kg
(c) 300 kg
(d) 331 kg
(e) 195 kg
3-135 Water is boiled at 1 atm pressure in a coffee maker
equipped with an immersion-type electric heating element.
The coffee maker initially contains 1 kg of water. Once boil-
ing started, it is observed that half of the water in the coffee
maker evaporated in 10 minutes. If the heat loss from the cof-
fee maker is negligible, the power rating of the heating ele-
(a) 3.8 kW
(b) 2.2 kW
(c) 1.9 kW
(d) 1.6 kW
(e) 0.8 kW
3-136 A 1-m³ rigid tank contains 10 kg of water (in any
phase or phases) at 160°C. The pressure in the tank is
(a) 738 kPa
(b) 618 kPa
(c) 370 kPa
(d) 2000 kPa
(e) 1618 kPa
3-137 Water is boiling at 1 atm pressure in a stainless steel
pan on an electric range. It is observed that 2 kg of liquid
water evaporates in 30 min. The rate of heat transfer to the
(a) 2.51 kW
(b) 2.32 kW
(c) 2.97 kW
(d) 0.47 kW
(e) 3.12 kW
3-138 Water is boiled in a pan on a stove at sea level.
During 10 min of boiling, it is observed that 200 g of
water has evaporated. Then the rate of heat transfer to the
(a) 0.84 kJ/min
(b) 45.1 kJ/min
(c) 41.8 kJ/min
(d) 53.5 kJ/min
(e) 225.7 kJ/min
3-28 A 1.8-m³ rigid tank contains steam at 220°C. 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.
3-31 10-kg of R-134a fill a 1.348-m³ rigid container at an
initial temperature of -40°C. The container is then heated
until the pressure is 200 kPa. Determine the final temperature
and the initial pressure. Answers: 66.3°C, 51.25 kPa
3-38 Three kilograms of water in a container have a pres-
sure of 100 kPa and temperature of 150°C. What is the vol-
ume of this container?
3-43 Water initially at 200 kPa and 300°C is contained
in a piston-cylinder device fitted with stops. The water is
allowed to cool at constant pressure until it exists as a satu-
rated 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, intermedi-
ate, 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.
3-44 Saturated steam coming off the turbine of a steam
power plant at 40°C condenses on the outside of a 3-cm-
outer-diameter, 35-m-long tube at a rate of 130 kg/h. Deter-
mine the rate of heat transfer from the steam to the cooling
water flowing through the pipe.
A piston-cylinder device contains 0.005 m³ of
EES liquid water and 0.9 m³ of water vapor in equi-
librium at 600 kPa. Heat is transferred at constant pressure
until the temperature reaches 200°C.
(a) What is the initial temperature of the water?
(b) Determine the total mass of the water.
(c) Calculate the final volume.
(d) Show the process on a P-v diagram with respect to satura-
3-84 Determine the specific volume of superheated water
vapor at 3.5 MPa and 450°C based on (a) the ideal-gas
equation, (b) the generalized compressibility chart, and
(c) the steam tables. Determine the error involved in the
first two cases.
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