View Full Version : Alcohols and phenols
Ebudo
Oct 28, 2009, 04:40 PM
PHENOLS: please I was told by my teacher that phenols dissolve in alkali but not in sodium carbonate... I would love to know why...
ALCOHOLS: and also, why is it that resonance is not possible in alcohols were the hydrogen atom of the OH group is held more strongly to the Oxygen.. thankss...
Unknown008
Oct 29, 2009, 08:55 AM
Phenol: Phenol is acidic. The oxygen in the OH group has part of its electrons delocalised around the benzene ring. This loosens the O-H bond, and allows it to dissociate into C_6H_6O^- and H^+. Now, phenol is acidic enough to react with alkalis and some bases. However, it is not acidic enough to displace carbon dioxide from carbonates (it depends on it's dissociation extent)
Alcohols: By resonance, you mean the delocalisation of electrons?
Ebudo
Oct 29, 2009, 04:21 PM
Thanks a lot for answering..
Alcohols: yes I mean the delocalisation of electron...
Unknown008
Oct 29, 2009, 11:01 PM
Well, where can they possibly go if they get delocalised? In the case of phenol, they get in the ring, enriching the latter in electrons. Electrons never go in a solution. You may think of them as getting drowned in solution.
By the way, I would like to know what makes you think they should get delocalised, so that I may understand what are you getting at, if possible. :)
Ebudo
Oct 30, 2009, 12:08 AM
Actually, I was just curious to know.. that's all... thanks anyway...
Unknown008
Oct 30, 2009, 12:28 AM
It's okay. I know sometimes, questions just get there, but at other times, we think of something, then another thing, then another, and we finally get to a question, just like yours.
I'll add something:
When you have a polymer, of alternate 'single, double, single, double,. ' bonds between carbon atoms, the polymer tends to have the electrons forming the double bond delocalised and the polymer can conduct electricity. This is nowadays used in the production of touch screens :)