7aCDW11quiz2

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P7A Quiz2a DL Sec ___ Name ( last ) _______________________ ( first ) ____________________ I certify by my signature that I will abide by the code of academic conduct of the University of California. Signature ________________________________________ THERE IS A SECOND PROBLEM ON THE BACK Rubric Codes: 1. (12pts) Energy is added as heat to a 1 kg. sample of material at a constant rate. The sample is initially a solid at 80 K. Enough energy is added to completely melt and vaporize the sample. The heating curve follows: T f 300 K 200 K 100 K 80 K 160 J 400 J 1000 J 1600 J 1800 J 2100 J a) From the information provided, determine which is greater, the heat of vaporization or the heat of melting? Explain how you know. (4pts) b) From the information provided, determine in which phase, solid, liquid or gas, the sample has the greatest heat capacity?

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Unformatted text preview: Explain and support your answer with calculations. (4pts) c) Calculate the final temperature, T f , exactly. (4pts) 2) (8 pts) 2.5 kg of liquid mercury at 274 K is added to 3.3 kg of water at 300 K. The new mixture is allowed to come to thermal equilibrium in a sealed container. Substance Specific Heat (kJ/kg*K ) Mass (kg) Initial Temperature (K ) Mercury .140 2.5 274 Water 4.18 3.3 300 There are no phase changes involved and you may assume no heat enters or leaves the container. a) Draw a complete energy interaction diagram for this problem. b) Clearly write down the expression, using conservation of energy, which will allow you to find the final equilibrium temperature of the mixture. YOU DO NOT HAVE TO SOLVE FOR THE FINAL TEMPERATURE VALUE !!!!!!!!!!!!!!...
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