Hexane is soluble in alcohol and ethyl alcohol soluble in water explain.?

1 Answer
Mar 12, 2018

Well what has #"ethyl alcohol"# got that #"hexane"# ain't got?

Explanation:

#"Ethyl alcohol"="H"_3"CCH"_2"OH"#...#"normal boiling point,"# #78# #""^@C#.

#"n-hexane"="H"_3"C(CH"_2")"_4"CH"_3#...#"normal boiling point,"# #68# #""^@C#.

Both solvents are mutually soluble, but ONLY #"ethyl alcohol"# is soluble in water. Why so? Well, the alcohol contains an hydroxyl group, i.e. it is in effect half a water molecule, the which allows solubility in the aqueous phase. The elevated boiling point of the alcohol, with respect to the long chain alkane, is also evidence of a strong intermolecular force. For the alkane, only dispersion force operates intermolecularly.

On the other hand, #"methyl alcohol"#, whose hydrocarbyl tail is REDUCED, is INSOLUBLE in #"hexane"#, and has a normal boiling point of #64.7# #""^@C#. How would you rationalize these data?