2) A 100-g block of copper at -30°C is placed in an insulated container holding 250 ml of water at 1°C. Specific heat at constant pressure for water, copper and ice: cw=4.186 kJ/(kgK) c.=0.386 kJ/(kgK), c=2.093kJ/kg. Latent heat of fusion for water L=333 kJ/kg. Everything happens at 1 atm. a) If we assume that none of the water freezes and balance energy, we find a final temperature <0°C. Is this possible? b) If we assume that all of the water freezes and balance energy, we find a final temperature >0°C. Is this possible? c) Actually, only some of the water freezes. What is the final temperature of the system? d) How much water actually freezes?

2) A 100-g block of copper at -30°C is placed in an insulated container holding 250 ml of water at 1°C. Specific heat at constant pressure for water, copper and ice: cw=4.186 kJ/(kgK) c.=0.386 kJ/(kgK), c=2.093kJ/kg. Latent heat of fusion for water L=333 kJ/kg. Everything happens at 1 atm. a) If we assume that none of the water freezes and balance energy, we find a final temperature <0°C. Is this possible? b) If we assume that all of the water freezes and balance energy, we find a final temperature >0°C. Is this possible? c) Actually, only some of the water freezes. What is the final temperature of the system? d) How much water actually freezes?

College Physics

10th Edition

ISBN:9781285737027

Author:Raymond A. Serway, Chris Vuille

Publisher:Raymond A. Serway, Chris Vuille

Chapter10: Thermal Physics

Section: Chapter Questions

Problem 7WUE: One way to cool a gas is to let it expand. When a certain gas under a pressure of 5.00 106 Ha at...

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One way to cool a gas is to let it expand. When a certain gas under a pressure of 5.00 106 Ha at 25.0C is allowed to expand to 3.00 times its original volume, its final pressure is 1.07 106 Pa. (a) What is the initial temperature of the gas in Kelvin? (b) What is the final temperature of the system? (See Section 10.4.)
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