[suadjama]

Thank youu!!

[suadjama]

Thanks! I can't find the markscheme though?

[Hoomz]

(Original post by suadjama)
Thanks! I can't find the markscheme though?

http://www.google.co.uk/url?sa=t&rct...mDsflw&cad=rja

[arvin_infinity]

(Original post by kickasskaz01)
same!

Post the one you hate the most! might be able to help you

[frizz101]

chemistry is so awesome

[silver0]

Does anyone have any tips on Chemistry revision? how to revise efficiently etc?

[the_alybot]

Hey guys I was wondering if you could help me out here? I'm currently revising Spectroscopy and I'm on spin spin coupling in proton NMR. Do we have to know why and how it occurs or do we just have to know how to interpret the splitting patterns?

[Lindizya]

^ we need to know how to interpret the splitting pattern e.g n+1 rule

[arvin_infinity]

(Original post by the_alybot)
Hey guys I was wondering if you could help me out here? I'm currently revising Spectroscopy and I'm on spin spin coupling in proton NMR. Do we have to know why and how it occurs or do we just have to know how to interpret the splitting patterns?

Just how to interpret it ..however if you do end up learning it please teach me a bit
My teacher just skipped it

[kickasskaz01]

I love this unit at the moment! It seems so simple and logical!

[Lindizya]

Has anyone got advice on how to tackle the questions which ask you to compare benzene, cyclohexene and phenol where do I start?

[AreebWithaHat]

(Original post by Lindizya)
Has anyone got advice on how to tackle the questions which ask you to compare benzene, cyclohexene and phenol where do I start?

I start with their basic features e.g.
benzene has delocalised electrons spread across 6 carbon atoms
cyclohexene has localised electrons between two carbon atoms
phenol has lone pair of electron on O atom that is drawn into ring and activates it.

Then compare electron densities:
phenol and cyclohexene have higher electron densities than benzene.

So what does this mean?
phenol and cyclohexene have sufficient electron density to induce dipoles in halogens e.g-bromine.
benzene does not have a high enough e.d to polarise bromine.

Hope this helps

[Lindizya]

^thank you that helps a lot

[AreebWithaHat]

Has anyone got any advice for those odd 1 mark impurities questions?

[arvin_infinity]

(Original post by areebmazhar)
Has anyone got any advice for those odd 1 mark impurities questions?

You mean recrystallisation I guess..Well if thats what you mean I only have memorised it and have no idea how its done whatsoever
Anyhow, type out the question so people know what you are asking

[AreebWithaHat]

(Original post by arvin_infinity)
You mean recrystallisation I guess..Well if thats what you mean I only have memorised it and have no idea how its done whatsoever
Anyhow, type out the question so people know what you are asking

Question 5bii on here http://www.ocr.org.uk/download/pp_10...n_gce_f324.pdf
Apparently the answer is HO-CH2-CH2-NH-CH2-CH2-OH and I can see its a double substitution of epoxyethane with NH3.
Then there was 5bii on here http://www.ocr.org.uk/download/pp_10...n_gce_f324.pdf.
But after having done them again, I've realised that the NH2 or NH3 group has multiple hydrogens substituted.

So in case anyone else is interested, impurities=multiple substitution of NH group.
Thanks anyway though

[AreebWithaHat]

(Original post by arvin_infinity)
You mean recrystallisation I guess..Well if thats what you mean I only have memorised it and have no idea how its done whatsoever
Anyhow, type out the question so people know what you are asking

Can I ask which past papers are you doing? There's only been like 4 for our spec so far, but there used to be chains, rings and spectroscopy papers. Do you know where I can get these from?
Thanks a lot

[arvin_infinity]

(Original post by areebmazhar)
Question 5bii on here http://www.ocr.org.uk/download/pp_10...n_gce_f324.pdf
Apparently the answer is HO-CH2-CH2-NH-CH2-CH2-OH and I can see its a double substitution of epoxyethane with NH3.
Then there was 5bii on here http://www.ocr.org.uk/download/pp_10...n_gce_f324.pdf.
But after having done them again, I've realised that the NH2 or NH3 group has multiple hydrogens substituted.

So in case anyone else is interested, impurities=multiple substitution of NH group.
Thanks anyway though

Just looked at the first one.. the fact that you see its a double substitution its a lot to be happy for
I mean that question is the most demanding question on the paper..I would love to see if anyone can come up with some tips for that!

[AreebWithaHat]

(Original post by arvin_infinity)
Just looked at the first one.. the fact that you see its a double substitution its a lot to be happy for
I mean that question is the most demanding question on the paper..I would love to see if anyone can come up with some tips for that!

Yeah, both of those were some form of double substitution. I think for "impurity" questions, this could be some pattern. Always look for a double sub maybe?

[arvin_infinity]

(Original post by areebmazhar)
Yeah, both of those were some form of double substitution. I think for "impurity" questions, this could be some pattern. Always look for a double sub maybe?

I dont why you like saying impurities instead of saying bi-product !! Still havent looked at 2nd one just cuz you say its the same.
double sub?! yes (if its the right term to use for further substitution )
I would say why not! so you think its gonna come up with the same pattern