A block of material has a heat capacity given by C = AT , where T is the temperature and A=6.0 JK^−2. In this question you may take 0 ◦C = 273 K
The block, initially at 127 ◦C is inserted into a reservoir of water at 27 ◦C. Find the changes in the entropy of the reservoir, the block and the overall change in entropy. Is this a reversible process? Explain why or why not.
A block of material has a heat capacity given by C = AT , where T...
i got this question wrong. the book previously said that the
units of entropy are J/(mol*K). you can get mol with the grams that
they gave, so why not use it?
Example: If, in a reversible process, 6.66 x 10 J of heat is used to change a 200 g block of ice to water at a temperature of 273 K, what is the change in the entropy of the system? (Note: The heat of fusion of ice = 333...
A 75 kg aluminium ingot (initially at 58 °C), and a 48 kg granite block (initially at 62 °C)) are lowered into a large water reservoir at 17 °C. Both the aluminium ingot and granite block reach the same temperature as the water, due to heat transfer between the blocks and the reservoir water. (a) Determine the total entropy change for this process. (12 marks) (b) With the aid of a diagram, briefly discuss the reversibility/irreversibility of all the heat...
A 46 kg copper block initially at 140°C is dropped into an insulated tank that contains 90 L of water at 10°C. Determine the final equilibrium temperature and the total entropy change for this process. The specific heat of water at 25°C is Cp= 4.18 kJ/kg-K. The density of water is 997 kg/m3. The specific heat of copper at 27°C is cp=0.386 kJ/kg-K. Water Copper 90 L The final equilibrium temperature is 15.85 K. The total entropy change during this...
A 70-kg copper block initially at 140'C is dropped into an insulated tank that contains 90 L of water at 10'C. Determine the final equilibrium temperature and the total entropy change for this process. The specific heat of water at 25°C is cp=418 kJ/kg-K. The density of water is 997 kg/m2. The specific heat of copper at 27°C is Cp=0.386 kJ/kg.K. Water Copper 90 L The final equilibrium temperature is OK The total entropy change during this process is OKJ/K.
A 34 kg iron block and a 48-kg copper block, both initially at 80°C, are dropped into a large lake at 15°C. Thermal equilibrium is established after a while as a result of heat transfer between the blocks and the lake water. Determine the total entropy change for this process. The specific heat of Iron at room temperature is cp0.45 kJ/kg.K. The specific heat of copper at 27°C is ep 0,386 kJ/kg.K. Iron Lake 15°C Copper The total entropy change...
9. Overall change in entropy. A copper penny, initially at temperature Ti, is placed in contact with a large block of ice that serves as a heat reservoir and has a constant temperature Tres (well below freezing). Take the penny's heat capacity to have the constant value C, and specify Ti 7 Tres (by a finite amount). The following questions pertain after the joint system has come to thermal equilibrium. (a) What are the entropy changes of the penny and...
Problem 2: (10 pts) A 30-kg iron block at initial temperature 200°C and a 40-kg copper block at initial temperature 100°C are dropped into a very large lake at 20°C. Thermal equilibrium is established after a while as a result of heat transfer between the blocks and lake water. Both blocks have constant specific heats, i.e. Ciron = 0.45 kJ/kg. K and Ccopper = 0.386 kJ/kg. K. Hint: The very large lake can be treated as a heat reservoir and...
A block of iron ore A of mass m = 350 kg and specific heat capacity C = 460 kJ/(kg·K) obeys the constitutive relations where T is temperature. The block of metal is initially at temperature T1 = 700 K and it is placed in a perfectly-sealed, constant-pressure container B containing 64 kg of air initially at 320 K and atmospheric pressure 101.3 kPa. The air in container B can be modeled as a perfect gas with specific heat capacity...
a) Define entropy as a thermodynamic state variable. b) Determine the final temperature when a block of copper at 0 °C is added to 1.0 kg liquid water at 80 °C in an insulated container at constant atmospheric pressure. The copper has a heat capacity of 0.01 kJ kg1 and the specific heat of water is 4.2 kJ kg1 K (both assumed constant with temperature) c) Calculate the change in entropy of the system in b). s it appropriate to...
6: A 50 kg copper block initially at 80 C is dropped into a lake at 15 C. Thermal equilibrium is established after a while as a resul the lake water. The specific heat copper at roorm temperature is c,-0.386 kJ/kg°C. Assuming the surroundings to be at 20 c t of heat transfer between the b lock and a. Determine the internal energy change and the entropy change of the copper. b. Determine the total entropy change for this process....