double_bond
Harmless
Posts: 2
Registered: 15-7-2006
Member Is Offline
Mood: No Mood
|
|
doubt about benzene
hi
I studied that benzene is an unsaturated compound, but one of my collegue says that it is saturated and it gives a negative test for
unsaturation ie..bromine water test(Bayers test) and oxidation test using KMnO4 . He says that benzene is a saturated hydrocarbon, and benzoic acid
is saturated carboxylic acid? who is right me or my friend? please clear my doubt
|
|
Endo
Hazard to Others
Posts: 124
Registered: 5-1-2006
Location: USA
Member Is Offline
Mood: Cold
|
|
Double,
I suggest you just break out your chemistry book and look up aromatic compounds[benzene]. Or, you could just use any of hundreds of tools available
to you and look up its structure. (saturated compounds have no double bonds). I really don't think you need to bother us to find this answer.
|
|
Flip
Hazard to Others
Posts: 116
Registered: 7-12-2005
Member Is Offline
Mood: No Mood
|
|
Hey there. So of course you are correct, aromacity is considered unsaturation. The biggest thing that could mess some people up when considering
this test on benzene is that aromatic rings are much less reactive than alkenes/ alkynes are. Throw in some free radical and ionic substitutions that
can discharge the bromine color and the casual observer could have a fair probability of a false negative. These aren't what I would use on aromatic
compounds though, a Friedel-Crafts test would work and you'd get to do a nifty reaction.
|
|
Nick F
Hazard to Others
Posts: 439
Registered: 7-9-2002
Member Is Offline
Mood: No Mood
|
|
It is unsaturated, but aromatic. This aromaticity stabilises the molecule by ~150 kJmol-1, which accounts for fact that benzene does not behave as a
"normal" unsaturated compound.
|
|
Nerro
National Hazard
Posts: 596
Registered: 29-9-2004
Location: Netherlands
Member Is Offline
Mood: Whatever...
|
|
As Flip said, when you do a Friedel-Crafts Alkylation (eg. C6H6 + Cl2 -AlCl3-> C6H5Cl + HCl) it could only work if the molecule is unsaturated. And
Hey presto! it works Tell your collegue that
#261501 +(11351)- [X]
the \"bishop\" came to our church today
he was a fucken impostor
never once moved diagonally
courtesy of bash
|
|