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Homework Help: Heat question

  1. Feb 1, 2012 #1
    You place 1.0 kg of ice ( at 0 deg c) in a pot and heat t until the ice melts and the water boils off, making steam. How much heat must you apply to achieve this?

    Also, a printing plate of 20 kg is made of lead. After casting, the solid lead cools to 90 deg c . It is then dropped into a 200 l tank of water initially at 25 deg c. What is the final equilibrium temp?

    I just don't even know how to start these problems, but I'm sure it's easy. Please help cause I don know what to do!!!


    Is what I think you need.

  2. jcsd
  3. Feb 2, 2012 #2
    Hi calculusisrad,
    Problem #1:
    You have two transitions here if you like. Ice to water, and water to steam. Therefore you will have to consider multiple energies to break the bonds and also raise the temperature of the ice/water (latent heat/sensible heat).

    Problem #2:
    Here, the energies (Q=mcΔt) for the plate and tank of water are equal.

    Hope this helps.
  4. Feb 2, 2012 #3


    User Avatar

    Staff: Mentor

    latent heat of melting
    latent heat of vaporization
    table of specific heats
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