1
$\begingroup$

I've been struggling with the various methods of purification of organic compounds. If a question comes up in my examination, asking me to explain steam distillation in my own words, I'd like to know if this applies and if this is accurate.

i) Steam distillation is utilized to separate volatile constituents which are immiscible with water but steam volatile.

ii) Steam from a steam generator is passed through a heated flask which contains the liquid to be distilled.

iii) The volatile component separates and thusly, one obtains a mixture of steam and the volatile organic compound.

iv) This is then condensed and separated by means of a separatory funnel.

In steam distillation, the liquid boils when the sum of vapour pressured due to organic liquid and that due to water become equal to the atmospheric pressure. i.e Patm=Pw+Pc

Since $Pc<P$ ; liquid vaporises at temperature lower than its boiling point. That is, if water insoluble substance and water are the components, the mixture boils at a temperature close to, but below 373K. Example: Aniline-Water

Please be highly specific. There should be no error, however minute. Many thanks.

$\endgroup$
2
$\begingroup$

You have it right on all counts. But, to clarify...

i) Steam distillation is used to separate steam-volatile organic components of a mixture from non-volatile ones (not from each other, however). It is most useful for higher boiling, relatively non-polar organic compounds that are immiscible with water.

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.