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Homework Help: Physical Chemistry - vapor pressures

  1. Sep 25, 2010 #1
    1. The problem statement, all variables and given/known data

    At what temperature will isopropanol (Tbp = 82.5C) and carbon tetrachloride (Tbp = 76.7C) have the same vapour pressure? For isopropanol and carbon tetrachloride, the standard enthalpies of vaporization are 32.54 kJ mol-1 and 44.0 kJ mol-1, respectively.

    2. Relevant equations
    Clapeyron Equation???


    3. The attempt at a solution
    I don't really know how to get started.

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


    2. Relevant equations



    3. The attempt at a solution
    1. The problem statement, all variables and given/known data



    2. Relevant equations



    3. The attempt at a solution
    1. The problem statement, all variables and given/known data



    2. Relevant equations



    3. The attempt at a solution
     
  2. jcsd
  3. Sep 25, 2010 #2

    Borek

    User Avatar

    Staff: Mentor

    You are right about using Clapeyron equation.

    What does boiling point mean? How is it related to vapor pressure?

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  4. Sep 25, 2010 #3
    The only relationship I know between boiling point and vapor pressure is that the boiling point is the temperature where the vapor pressure of a liquid is equal to external pressure.
     
  5. Sep 27, 2010 #4

    Borek

    User Avatar

    Staff: Mentor

    External pressure is 1 atm - that means you are given p1, T1 and vaporization enthalpy for each substance. That's enough to find any p2/T2 pair.
     
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