Question

A cooper block having a mass of 10 kg and at a temperature of 800 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 for copper.

Homework Answers

Answer #1

Heat gained by water = heat released by copper

Mass x Cp x (T -T1) = mass of Cu x Cp x (T2-T)

100 kg x 4.185 kJ/kg-K x (T - 290)K = 10 kg x 0.398 kJ/kg-K x (800 - T)K

105.1507 (T - 290) = 800 - T

105.1507 T - 30493.72 = 800 - T

T = 294.8 K

Part a

entropy change for the block

S1 = mCp ln (T/T2)

= 10 kg x 0.398 kJ/kg-K x ln (294.8/800)

= - 3.973 kJ/K

entropy change for the water

S2 = mCp ln (T/T1)

= 100 kg x 4.185 kJ/kg-K x ln (294.8/290)

= 6.8701 kJ/K

Entropy change of process = S1 + S2

= - 3.973 + 6.8701

= 2.897 kJ/K

Part b

maximum amount of work can be obtained when efficiency is maximum

Efficiency of Carnot engine = 100% = 1

Maximum work obtained = efficiency x Qh

= 1 x 100 kg x 4.185 kJ/kg-K x (294.8 - 290)K

= 2008.8 kJ

Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
A 50 kg copper block initially at 350 oC is quenched in a closed, rigid insulated...
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.
A block of copper has a mass of 100 kg and an initial temperature of 900...
A block of copper has a mass of 100 kg and an initial temperature of 900 K. Copper can be modeled as an incompressible substance with a specific heat capacity of 0.4 kJ/kg-K. a.) The copper block is dropped into a large lake at 300 K and allowed to come to thermal equilibrium. How much entropy is generated (kJ/K)? b.) If a reversible heat engine were connected between the lake and the copper block and operated until the temperature of...
A 1.05 kg block of copper at 100°C is placed in an insulated calorimeter of negligible...
A 1.05 kg block of copper at 100°C is placed in an insulated calorimeter of negligible heat capacity containing 3.50 L of liquid water at 0.0°C. (a) Find the entropy change of the copper block. J/K (b) Find the entropy change of the water. J/K (c) Find the entropy change of the universe. J/K
A copper block of mass 17.5 kg initially at 481 K is immersed in 31.5 kg...
A copper block of mass 17.5 kg initially at 481 K is immersed in 31.5 kg of water initially at 298 K. CP,m(H2O,l)=75.3J⋅K−1⋅mol−1 CP,m(Cu,s)=24.4J⋅K−1⋅mol−1 Assume that the heat capacity of Cu remains constant at its 298.15 K value over the temperature interval of interest. 1) Calculate ΔS for the water. 2) Calculate ΔS for the Cu block.
A 41.6 g block of copper whose temperature is 372 K is placed in an insulating...
A 41.6 g block of copper whose temperature is 372 K is placed in an insulating box with a 59.3 g block of lead whose temperature is 146 K. (a) What is the equilibrium temperature of the two-block system? (b) What is the change in the internal energy of the two-block system between the initial state and the equilibrium state? (c)What is the change in the entropy of the two-block system? The heat capacities of copper and lead are 386...
A 16.2 g block of copper whose temperature is 417 K is placed in an insulating...
A 16.2 g block of copper whose temperature is 417 K is placed in an insulating box with a 122 g block of lead whose temperature is 103 K. (a) What is the equilibrium temperature of the two-block system? (b) What is the change in the internal energy of the two-block system between the initial state and the equilibrium state? (c) What is the change in the entropy of the two-block system? The heat capacities of copper and lead are...
A 4.2-kg block of ice originally at 263 K is placed in thermal contact with a...
A 4.2-kg block of ice originally at 263 K is placed in thermal contact with a 13.4-kg block of silver (cAg = 233 J/kg-K) which is initially at 1075 K. The H2O - silver system is insulated so no heat flows into or out of it. 1) At what temperature will the system achieve equilibrium? 2) What will be the phase of the H2O at equilibrium? Solid (ice) Liquid (water) Gas (vapor)
A block of an alloy of mass 36.0 g and at a temperature of 275.21 K...
A block of an alloy of mass 36.0 g and at a temperature of 275.21 K is placed in a calorimeter containing 34.0 g of water at 366.25 K. If the final temperature of the alloy and water is 324.25 K, calculate the specific heat (in J/g/K) of the metal. The specific heat of water is 4.184 J/g/K. Express your answer to three significant figures in scientific notation.
Please Show all work, thank you! A copper block with a mass of 400 grams is...
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...
21. The initial temperature of an iron block of unknown mass is 83 oC. The iron...
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...
ADVERTISEMENT
Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

Ask a Question
ADVERTISEMENT