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Homework Help: Calculating the Volume of Liquid as a fraction of the Volume of Gas for Water at 25°C

  1. Sep 19, 2010 #1
    1. The problem statement, all variables and given/known data

    'Look up the density and vapour pressure of water at 25°C, and use the ideal gas law to calculate Vliq as a fraction of Vg for one mole of water at 25°C'

    Ok so, Density of water at 25°C & 1atm is: 0.997 g/cm³.
    The vapour pressure of water at 25°C and 1atm is: 3.1691 kPa

    2. Relevant equations

    The ideal gas law: PV=nRT
    Also, I think perhaps the Clausius-Claperon equation might be used?!

    3. The attempt at a solution

    I think the question is a little ambiguous, so I am unsure of how to approach this question.

    For a start, I can use the ideal gas equation to work out the volume of one mole of water vapour at 25°C and 1atm:

    V=nRT/P= (1mole)x(8.314J/Mol.K)x(298K)/101,325Pa= 0.0245m³

    However, i'm stuck now as to what is the next logical step!!!
  2. jcsd
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