ATAR Notes: Forum
VCE Stuff => VCE Science => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Chemistry => Topic started by: Dark Horse on April 06, 2009, 10:32:51 pm
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Hey guys, in the molecule phenol (C6H5OH)-A benzene ring with one of the H atoms substituted for an OH, how many carbon and hydrogen environments are there? Thanks :)
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According to my teacher: 4 hydrogen and 4 carbon environments.
However, I can't see it
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C2/C6 equivalent (H's on these Cs are equivalent too)
C3/C5 equivalent (H's on these Cs are equivalent too)
C1
C4
and the H on the OH and the H on C4
therefore, 4 carbon environments and 4 H environments
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According to my teacher: 4 hydrogen and 4 carbon environments.
However, I can't see it
As chem-nerd said:
(http://img14.imageshack.us/img14/2945/bezene.png)
On the 1st carbon atom, clearly the C is in a different environment because it is with an OH
Now on 2nd carbon atom, it has a single bond left of it and a double right of it. C6 also has this formation. 2nd C environment.
On the 3rd carbon atom, it has a double bond to the left and a single bond to the right. C5 same formation. 3rd C environment.
C4 is different from C1 because it is bonded to a H not a OH.
Hence 4 C environments.
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try not to think of those double and single bonds as being 'set' in place. they can move around the benzene ring (hence why it's usually drawn with a circle in the middle).
the different environments are produced by the different neighbours.
for C2/C6 they have a C-O on one side and a C-C on the other
for C3/C5 they have a C-C-O on one side and a C-C-C on the other
for C4 it has a C-C-C on both sides
and C1 is clearly different due to the O
it's the same for the H environments
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here's a picture:
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Thanks guys, i get it now! =P