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Can you show me if i did these calculations right?

  1. Jul 25, 2009 #1
    1. The problem statement, all variables and given/known data

    The specific heat of mercury is .03 cal/g C and its boiling point is 357 C. The specific heat of water is 1 cal/g C. It takes 65 calories of energy to vaporize one gram of mercury and 540*(edit) calories to vaporize 1 gram of water. If both substances begin at room temperature ( about 22 C) does it take more energy to boil a gram of mercury or a gram of water? Show your calculations.


    Mercury Calculations:


    Water calculations:


    3. The attempt at a solution


    I will just go straight to the trying to solve it out......

    Mercury Calculations.....

    1 x .03 x ( 357-22) +65 = energy required for mercury
    1 x .03 x 335 + 65
    1 x 10.05 + 65 =
    75.05 ........did i do this right?? by your calculations???


    Water Calculations:

    1 x 1 x (100 -22) + 540 = energy required for water
    1 x 1 x 78 + 540
    78+540 =
    618 = cal energy required for water.......So did i do both right ....
    .....so basically it required more energy to boil a gram of water...
     
    Last edited: Jul 25, 2009
  2. jcsd
  3. Jul 25, 2009 #2

    cepheid

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    The 540 for energy of vaporization of water is not consistent with what is given in your problem (430). Aside from that, the calculations seem alright.
     
  4. Jul 25, 2009 #3
    Your completely right cepheid i messed up ....instead of 430 it should had been 540 ....but does it seem right??? now that its 540?
     
  5. Jul 26, 2009 #4

    cepheid

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    As far as I can see, your calculations look fine. I don't see any obvious errors with the method or with the arithmetic.
     
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