Question

A 50 kg copper block initially at 350 oC is quenched in a closed, rigid insulated tank containing 120 L of liquid water at 25 oC. Specific heat of copper, Cc = 385 J/(kgK), specific heat of liquid water, Cw = 4180J/(kgK). (i) Calculate the entropy change (kJ/K) of copper block. (ii) Determine the entropy change (kJ/K) of liquid water.

Answer #1

Initially (state 1) a well-insulated rigid tank contains 20 kg
of a saturated liquid-vapor mixture of water at 100 kPa and half of
the mass is in the liquid phase. An electric resistance heater
placed in the tank is now turned on and kept on until all the
liquid in the tank is vaporized (state 2). Determine (a) the
initial specific volume in m3/kg, (b) the final specific
entropy in kJ/kg.K and (c) change of entropy in kJ/K.

A cooper block having a mass of 10 kg and at a temperature of
800 K is placed in a well-insulated vessel containing 100 kg of
water initially at 290 K. Calculate:
a) Calculate the entropy change for the block, the water, and
the total process.
b) What is the maximum amount of work that could have been
obtained from the copper block and water in a Carnot engine? The
heat capacities are 4.185 kJ/kg/K for water and 0.398 kJ/kg/K...

Please Show all work, thank you!
A copper block with a mass of 400 grams is cooled to 77 K by
being immersed in liquid nitrogen. The block is then placed in a
Styrofoam cup containing some water that is initially at +50.0°C.
Assume no heat is transferred to the cup or the surroundings. The
specific heat of liquid water is 4186 J/(kg °C), of solid water is
2060 J/(kg °C), and of copper is 385 J/(kg °C). The latent...

Water of mass 2 kg in a closed, rigid tank is initially in the
form of a twophase liquid-vapor mixture. The initial temperature is
50° C. The mixture is heated until the tank contains only saturated
vapor at 110° C.
(i) Find the initial pressure, in kPa.
(ii) Find the work for the process, in kJ.
(iii) Find the heat transfer for the process, in kJ.

A rigid copper tank, initially containing 1 m3 of air at 295 K,
4 bar, is connected by a valve to a large supply line carrying air
at 295 K, 15 bar. The valve is opened only as long as required to
fill the tank with air to a pressure of 15 bar. Finally, the air in
the tank is at 310 K. The copper tank, which has a mass of 20 kg,
is at the same temperature as the...

An insulated aluminum calorimeter vessel of 150 g mass contains
300 g of liquid nitrogen boiling at 77 K. A metal block at an
initial temperature of 303 K is dropped into the liquid nitrogen.
It boils away 15.8 g of nitrogen in reaching thermal equilibrium.
The block is then withdrawn from the nitrogen and quickly
transferred to a second insulated copper calorimeter vessel of 200
g mass containing 500 g of water at 30.1 degrees celsius. The block
coolds...

An initially empty, well insulated, rigid tank with a volume of
2 m3 is fitted with a mixing device. The tank has two inlets and
zero outlets. One inlet is water at 1 MPa and 600◦C while the other
is saturated liquid water. Both enter the tank slowly. If the
amount of work done by the mixing device is 300 kJ, what must the
temperature of the saturated liquid water be if the same mass is
added through both inlets...

21. The initial temperature of an iron block of unknown mass is
83 oC. The iron block is cooled by dropping it into an
insulated container that contains 73 Liters of water at 23
oC. After reaching thermal equilibrium, the final
temperature of the iron block and water is measured as 39
oC. If the total entropy change for this
process is 2.5 kJ/oK, determine the mass of the iron in
kg. The specific heat for iron is 0.448 kJ/kg-oK and...

Consider an isolated system containing two blocks of copper with
equal mass. One block is initially at 0oC while the other is at
100oC.They are brought into contact with each other and allowed to
thermally equilibrate. What is the entropy change for the system
during this process? The heat capacity for copper is Cp =
24.5 [J/mol k]

A 200 g of copper, initially at 300o C, is dropped into a 350 g
of water contained in a 355 g aluminum calorimeter; the water and
the calorimeter are initially 15o C. If 25 g iron stirrer is used
to bring the mixture into thermal equilibrium, what is the final
temperature of the system? ( Assume that the stirrer is initially
at 15o C.) Specific heat of copper and aluminum are 0.092 cal/g oC
and 0.215 cal/g oC respectively....

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