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-   -   You are comparing two unknown liquids of similar molecular mass. (https://www.askmehelpdesk.com/showthread.php?t=494945)

  • Aug 4, 2010, 03:55 PM
    storm10
    You are comparing two unknown liquids of similar molecular mass.
    You are comparing two unknown liquids of similar molecular mass.
    Liquid A has a vapor pressure that is much higher than that of liquid B at the same temperature. Which of the following is the most
    Likely explanation for this observation.

    A. Liquid B is nonpolar and liquid A is polar, and the stronger intermolecular forces in liquid A give the liquid a
    Higher vapor pressure.

    B. Liquid B is polar and liquid A in nonpolar, and the stronger intermolecular forces in liquid B give the liquid a lower
    Vapor pressure.

    C. Both liquids are nonpolar.

    D. Both liquids are equally polar.
  • Aug 4, 2010, 05:35 PM
    DrBob1

    Storm:
    We want to hear your views on this subject -- what do you think the answer is?
    But here are some hints, or some food for thought:
    What effect does polarity have on boiling and melting points of compounds?
    Think of some compounds with similar molecular weights (for instance an alcohol and a hydrocarbon) Which ones are polar, which ones are nonpolar? Which ones boil higher than the others?
    Think it over and give us your answer.
  • Aug 4, 2010, 06:44 PM
    storm10

    A more polar molecule will have a higher melting point. A polar molecule will have a strong dipole-dipole bond and will require more energy to break that bond.

    Examples of polar molecules include ammonia and sugar . Polar molecules are generally able to dissolve in water due to the polar nature of water. Polar molecules have slightly positive and slightly negatively charged ends.

    Non-polar molecules

    Examples of non-polar compounds include fats, oil and petrol. Most non-polar molecules are water insoluble at room temperature. However many non-polar, such as turpentine, are able to dissolve non-polar substances.
  • Aug 4, 2010, 07:29 PM
    DrBob1

    Right on!
    So how do you think this relates to your question? Why does liquid A have a much higher vapor pressure than liquid B? Remember the two compounds have similar molecular weights
  • Aug 5, 2010, 01:27 AM
    Unknown008

    This is correct. Now, on the thinking part, what do you think is your liquid A and liquid B?

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