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Homework Help: Finding how much heat it takes to vaporize

  1. Jan 28, 2012 #1
    1. The problem statement, all variables and given/known data
    How much heat does it take to vaporize 600g of lead that is initially at 34°C?

    2. Relevant equations
    heat capacity=1.3X102

    3. The attempt at a solution
    ΔT = 1750°C - 34°C
    = 1716 ° C

    Q= m X c X ΔT
    = 0.6 X 1.3X102 X 1716
    =133,848 J

    Am I suppose to factor in the change of state? Is there latent vaporization?
  2. jcsd
  3. Jan 28, 2012 #2
    You've answered your own question. Think about the analogy of turning water to vapor.
  4. Jan 28, 2012 #3


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    Homework Helper

    Yes you are, Q = mcΔT just gives you the heat required to raise the temperature from 34°C to 1716°C.

    You just need to use Q=mlvap now and add them.
  5. Jan 29, 2012 #4


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    Homework Helper

    I not sure lead will even by molten at 34o, so you may have to melt it too. ANd is the heat capacity of solid lead and liquid lead the same?
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