Qualitative understanding of partition preferences

Introduction
Cavity model
Rules for partitioning
The cavity model in quantitative terms

Selftest
     1) What does the cavity model say?
           Answer
     2) Main interactions ... ?
           Answer
     3) Size of a solute  molecule ... ?
           Answer
     4) Size of the solvent  molecule ... ?
           Answer
     5) Interpretation of data
           Answer
     6) "Like dissolves like"
           Answer
     7) Concept maps
     8) Functional groups
           Answer
     9) Illustration by given data?
           Answer
     10) Evaluation of the software PcKocWIN
     11) H-bonds between given substances?
     12) Tendency to distribute
           Answer
     13) Gas chromatography
           Answer
     14) Henry's Law constant
           Answer
     15) Quiz
Problems
Intermolecular interactions in every day life
FAQ

6) "Like dissolves like"

 

Question:

a) You can often find that the rule "like dissolves like" is interpreted as "non-polar chemicals dissolve best in non-polar solvents" and "polar chemicals dissolve best in polar solvents". See for example the Wikipedia page on "Solvent" accessed in January 2008 (see Solvent-Wikipedia.pdf section marked in yellow). In this context polar solvents are typically defined as those that contain oxygen and/or nitrogen while non-polar solvents are defined as those that do not contain oxygen and/or nitrogen. Can you name some general cases that will proof these statements wrong? Use the classification that was introduced here.

b) In the same paragraph of the Wikipedia entry you can read that "The polarity can be measured as the dielectric constant or the dipole moment of a compound." Does that agree with what you have learned in this chapter?

 

proceed to answer