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Why should a distilling flask not be more than half filled?

  1. Jan 2, 2010 #1
    Hey,i have some lab report questions that i need to be checked. Ive submitted my report & the prof corrected it but the hard copy with the corrections remained with my partner. Now, my exam is on Monday n im left with the uncorrected soft copy.

    1. Why dosent all the liquid vaporize at once when the bp is reached?
    Not all the molecules in the liquid reach the boiling point all at once.The molecules
    on the surface have less pressure on them and gain enough energy to escape
    from the liquid so they vaporize first.

    2.Why should a distilling flask not be more than hlaf filled?
    If the flask is more than half full bumping occurs and the condenser as well
    as the distillate will be contaminated with undistilled liquid.

    3. What is the disadvantage of using a flask 4 to 5 times that of the used liquid?
    If the flask is too big for the amount of liquid,a lot of heat loss occurs from
    the flask and the rate of distillation is hence lowered.
  2. jcsd
  3. Nov 26, 2016 #2


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    Looks reasonable.
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