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Homework Help: Heat Transfer Equation

  1. Dec 13, 2006 #1
    im reviewing for my final in a few days an although this is a basic question i cant work out the correct answer for some reason. and i know i started the other thread below this one but i figured this was a different topic so the heading should be different lol

    1. The problem statement, all variables and given/known data

    A heat transfer of 8.8 x 10^5 J is required to convert a block of ice at -13°C to water at 13°C. What was the mass of the block of ice?

    2. Relevant equations

    Q=mc(ice)(tf-ti) + mLf + mc(water)(tf-ti)

    3. The attempt at a solution

    i tried: 8.8x10^5= m(2220)(13) + m(333) + m(4190)(13)
    i come out with the 10.52kg which is not correct.
    can someone help pinpoint what i am doing something wrong? thanks!
  2. jcsd
  3. Dec 13, 2006 #2


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    Staff Emeritus
    Science Advisor
    Gold Member

    Check those numbers. One of them is wrong - it's in the wrong units.

    You need to be very careful with your units!
  4. Dec 13, 2006 #3
    oh ok....the heat of fusion should be 333x10^3...solving it out then i would get 2.11 which is the correct answer. I need to be less careless with my units! lol thanks alot!! :D
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