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OCR A Chemistry F324 Rings, Polymers and Analysis Thu 26 Jan 2012

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Thank youu!! :smile:

Thanks! I can't find the markscheme though? :smile:

Reply 62

Hoomz

Original post by suadjama

Thanks! I can't find the markscheme though? :smile:

http://www.google.co.uk/url?sa=t&rct=j&q=ocr%20chemistry%20f324%20june%202011&source=web&cd=6&ved=0CEcQFjAF&url=http%3A%2F%2Fwww.a-levelchemistry.co.uk%2FOCR%2520Chemistry%2520A%2FUnit%25204%2FPast%2520Papers%2FF324_MS_June11.pdf&ei=UT3iToLPEIiTswaop8mOBA&usg=AFQjCNG_vhjcd6T508SGKNLrdXk0mDsflw&cad=rja

:smile:

Reply 63

arvin_infinity

Original post by kickasskaz01

same!

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

Reply 64

frizz101

chemistry is so awesome

Reply 65

silver0

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

Reply 66

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?

Reply 67

Lindizya

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

Reply 68

arvin_infinity

Original post by the_alybot

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

Reply 69

kickasskaz01

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

Reply 70

Lindizya

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

Reply 71

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 :smile:

Reply 72

Lindizya

^thank you that helps a lot

Reply 73

AreebWithaHat

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

Reply 74

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 :smile:

Reply 75

AreebWithaHat

Original post by arvin_infinity

Question 5bii on here http://www.ocr.org.uk/download/pp_10_jun/ocr_57550_pp_10_jun_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_jan/ocr_49036_pp_10_jan_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 :smile:

Reply 76

AreebWithaHat

Original post by arvin_infinity

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 :smile:

Reply 77

arvin_infinity

Original post by areebmazhar

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!

Reply 78

AreebWithaHat

Original post by arvin_infinity

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?

Reply 79

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! :wink:

so you think its gonna come up with the same pattern