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Homework Help: Latent Heat and phase changes (difficult)

  1. Apr 10, 2012 #1
    1. The problem statement, all variables and given/known data

    10g of ice at 0 degrees Celcius is combined with 2 g of steam at 100 degrees Celcius. Find the final temperature of the resulting water.

    2. Relevant equations

    mc(Tf- Ti)
    m(Lf) or m (Li)

    3. The attempt at a solution

    ΔQsteam=mLsteam+mcsteamTf-100 degrees celcius

    I set this equations to 0 and solve for Tf and i get this

    Tf=mCsTi+mLv-mLf/mCw+mCs and i get 93.9 degrees celcius and that is not the answer

    the answer is 40.4 degrees celcius. help?
  2. jcsd
  3. Apr 11, 2012 #2

    Solve the problem in two parts.

    1. Use first law of thermo to determine water temperature when steam's latent energy melts ice.
    2. Use mass weighted average to determine final temperature of mixture of two water solutions.

    The answer provided is correct.
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