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Homework Help: Heat-Equilibrium temp

  1. May 15, 2003 #1

    Dx

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    Hello,

    what will be the equilibrium temperature when a 270 g block of copper at 300 degrees C is placed in a 150 g Al calorimeter cup containing 820 g of water at 12 degree C?

    My answer is 20.2 C Is this correct?

    I done is like so 270 * (390)*(300-T) = (820)*(900)(T-12) sorry but i forgot where I referenced this formula, I think i am confused with this problem though. It doesnt seem right to me so i thought i would ask?

    Thanks!
    Dx
    :wink:
     
  2. jcsd
  3. May 15, 2003 #2

    Tom Mattson

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    Staff Emeritus
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    Gold Member

    The formula is:

    Heat lost by copper = Heat gained by water

    Where the heat (q) transferred to/from a body is given by:

    q=mC(Thot-Tcold)

    m=mass
    C=specific heat
    Thot=higher temp
    Tcold=lower temp

    The problem with your solution is that you need:

    Heat lost by copper = Heat gained by water and aluminum

    If you include the aluminum, you will get this right.
     
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