PHYSICS/CHEM: latent heat of fusion, specific heat?

As an attentive scientist, you put heat into a 0.500 kg sample of solid material at the rate of 10.0 kJ/min while recording its temperature as a function of time. You plot your data and obtain the graph shown in the figure

http://www.flickr.com/photos/39538700@N08/36621935...

Questions:

A) What is the latent heat of fusion for this substance? [in J/kg]

B) What is the specific heat capacity of the solid state of the material? [in J/(kg.K)]

C) What is the specific heat capacity of the liquid state of the material? [in J/(kg.K)]

1 Answer

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  • 1 decade ago
    Best Answer

    The temperature rose to a set point. That is the melting temperature. If you add 10,000 J/min and it stayed at that temperature for 1.5 min then you put in 15,000 J to melt the substance. It took 15,000 J to melt 0.500 kg so it would appear that the heat of fusion is 30 kJ/kg.

    The solid rose 15 degrees in one minute so it took 10,0 kJ to make 0.500 kg rise 15 degree. The Units tell you how to do the math!

    ALWAYS CHECK THE UNITS IN PHYSICS. JUST LOOKING AT THE UNITS OF THE ANSWER AND THE UNITS OF THE GIVEN DATA TELL YOU HOW TO DO THE PROBLEM.

    Oh yes, in big Universities the basic physics tests are multiple choice! How are you going to grade 150+ papers in a day?

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