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OCR F324 (Chains, rings and spectroscopy) 28/06/10

Hello, thought I'd start the thread =D.

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Reply 1
I really got to start learning all them god damn reactions....gonna start revision next week....Anybody already started?
Reply 2
I know o.O. Many many reactions.
Hey

This is probably the exam I'm most worried about at the moment :s-smilie:
I attempted to start revising this morning but I only got as far as aldehydes and ketones before ending up on here lol.
Reply 4
It's the synthesis chapter that's the real killer :frown:

We basically need to know the whole organic bit from AS as well in terms of reactions.
Has anyone got any useful revision posters/notes/cards for any of the topics in this module.. these normally get me started on revision :P
Reply 6
Not yet... well. I have cards, just not on the computer.. we could try to put overviews on here or something =D
Yeah that would be good :smile: Would help me alot.
Reply 8
I've made paper notes that I have already scanned in. I'll try and upload them tomorrow.
Reply 9
I'm glad someone has started this thread, anyone got any good reviosion resourses and sites???
I'm using a combination of the Heinemann book and the CGP revision guide...find them pretty helpful :smile:

xxx
Reply 11
cgp is awesome.
skatealexia
cgp is awesome.

:five:

Ok, I've now gone through the text book and revision guide for the first module (up to amines) so one down two to go :smile:

xxx
Reply 13
half of second and half of third module to go
It's going good so far. It's just a matter of getting your head down and learning it.
Still haven't started going through the Analysis module :s-smilie:

Hate that unit
chemguide.com is pretty good! Google it because I'm not too sure if that is the exact web address.
Reply 17
I've started my revision. Just thought I'd share what I've learnt so far on Benzene:

Problems with the Kekule structure of benzene:

1) Low reactivity - C=C present so should react in similar way to alkenes
- C=C should decolourise Bromine water.
But this does not happen, does not undergo electrophilic addition, undergoes electrophilic substitution.

2) Bond length - C-C and C=C have different bond lengths.

But this is not the case, according to xray studies all C-C bonds are the same, equal length.

3) Hydrogenation - expected enthalpy change of hydrogenation of benzene is -360kj mol-1, but the actual enthalpy change of hydrogenation of benzene is -208kj mol-1

>>> Therefore the actual structure of benzene is more stable than kekule's.


Delocalised model of benzene

- Trigonal Planar 120 degrees
- p-orbitals overlap around the whole of the ring forming a system of pie bonds.
- electron spread all the whole of the ring >>> delocalised >>> more stable.
- All C-C bonds are identical.

Nucleophilic substitution

Nitration of benzene:
Uses: Dyes and pharmaceuticals.

Conditions: Conc. H2SO4, conc. HNO3, 50 degrees C

C6H6 + HNO3 >>> C6H5NO2 + H20



Halogenation of benzene

- Only reacts in the presence of a halogen carrier - AlCl3, FeCl3

Benzene + Halogen >>> Halogenobenzene + Hydrogen Halide


The mechanisms for the nitration and halogenation of benzene are attached.

Enjoy.
Reply 18
Some flashcards summarising the spec you guys might find helpful

http://www.flashcardexchange.com/flashcards/view/944334

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