OCR Chemistry A F324 Rings, Polymers and Analysis Tue 19 June 2012

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is that good you mean 4/5 marks out of 5 ? if so what things i can put cause this is all the information as in the book when i revised ???

ok

Suggest why we use (CD3)2SO ?

No out of 8 marks mate.
Just talk about stuf like nylon-6,6 is not water soluble.whereas amino acids are n so.

Reply 581

otrivine

Original post by pete clark

Hmm, I don't think so, because on the compound you've given, if you saw an NMR spectra of that, you wouldn't get the Quartet at 3.4ppm, I dont think you'd get the marks buddy

so i will only lose 1 mark ? cause i got the peaks and i used the data to identify the strucutre ?

Reply 582

otrivine

Original post by Educator

No out of 8 marks mate.
Just talk about stuf like nylon-6,6 is not water soluble.whereas amino acids are n so.

where did u get solubility from it was not mentioned in the book >? only shows the structure and like the properties and the uses?

Reply 583

pete clark

Original post by otrivine

so i will only lose 1 mark ? cause i got the peaks and i used the data to identify the strucutre ?

hmm, I haven't got the markscheme up, so Im not sure. you wouldn't get 4, but you may get 2/3 :smile:

Reply 584

otrivine

Original post by pete clark

Hmm, I don't think so, because on the compound you've given, if you saw an NMR spectra of that, you wouldn't get the Quartet at 3.4ppm, I dont think you'd get the marks buddy

but the quartet represents CH3?

Reply 585

pete clark

Original post by otrivine

but the quartet represents CH3?

On an adjacent Carbon, yes. Your structure has no CH3 attached to another Carbon with a proton on :smile:

Reply 586

Educator

Original post by otrivine

where did u get solubility from it was not mentioned in the book >? only shows the structure and like the properties and the uses?

No.its all in the legacy papers.C'mon extra revision aint gna harm ya

Reply 587

otrivine

Original post by pete clark

On an adjacent Carbon, yes. Your structure has no CH3 attached to another Carbon with a proton on :smile:

so does the structure have to be branched but how do u know if there is going to be a branch or not do u have to like play around with the carbons and hydrogens ?cause if there are branches they should indicate the integration pattern?

and one thinghttp://pdf.ocr.org.uk/download/ms_11/ocr_61998_ms_11_gce_f324.pdf?
please the last question on carbon environment for the ethyl one c2h5 benzene i keep getting 5 environments not 6 ?

Reply 588

Bright

I think this paper requires a lot of thought and use of logic.. it's actually not bad, if only I spent longer revising for it.They put a lot of AS F322 into it but add an A* twist to it to distinguish between different candidates, don't let the complicated structures fool you the concept is ok! :]

lol this is what the chief examiner said when he came to my school

Reply 589

ChrisJ

Are we expected to know how to calculate the area under a curve in gas chromatography?
and if so, is the correct formula:
height x (width at half height)

Thanks

Reply 590

otrivine

Original post by Educator

No.its all in the legacy papers.C'mon extra revision aint gna harm ya

i did all the past papers from the ocr site and did the revision PACKS but nothing mentions on solubility ? can u write them down
i thought the revision packs i did are the legacy ones

Reply 591

pete clark

Original post by otrivine

There are 6 indeed. the CH3, the CH2, the carbon the ethyl group is attached to you, then work away from that carbon, think of the molecular symmetry

Reply 592

otrivine

Original post by pete clark

There are 6 indeed. the CH3, the CH2, the carbon the ethyl group is attached to you, then work away from that carbon, think of the molecular symmetry

well i used the c2 ones the ethyl and the carbon attached to them so 3 so far and the one next to it 4 then the other one 5 then the 6th???

Reply 593

Bright

Questions
Why is ethanol or methanol used industrially as the alcohol in making biodiesel and why must it be in excess?

Reply 594

Educator

Original post by otrivine

i did all the past papers from the ocr site and did the revision PACKS but nothing mentions on solubility ? can u write them down
i thought the revision packs i did are the legacy ones

My school provides me with all the chains,energy and resources papers all the way from 2002-2008.The name has been changed to rings and polymers now.But the content is 90% same.The question in there are actually relevant to our course you know.They have got so many questions that make you think 'ohh why didn't i know that,it's apparent'.Really straight forward thinking is involved but the way they put it is just different.Also when you go over the book you miss out some bits and bobs that are not worth looking at but these papers makes everything worth going over because they can ask you a whole question just on a simple paragraph from the book.
It's really worth looking and i have done all the new papers from 2010-2012 and the lowest i have got is probably 52/60.This makes me think that i know everything.But these papers challenge you and make you think twice to be honest.
A really good way of testing your knowledge.

Reply 595

Educator

They are renewable and efficient burners.
Can give you more reasons but i think 2 is enough lol.

Reply 596

otrivine

Original post by Bright

Questions
Why is ethanol or methanol used industrially as the alcohol in making biodiesel and why must it be in excess?

because it is renewable and made in excess so that it can produce a higher yield?

Reply 597

hetty123

Original post by hetty123

http://www.thestudentroom.co.uk/showthread.php?t=2013091
click on this and scroll down to moh.alt and there'll be a link to the jan 2012 paper and markscheme :biggrin:

Try that!

Reply 598

niaghez

Original post by Bright

Because you have to show that it differs from an alcohol, OH =alcohol functional group

oh yeah. LOL :colondollar:

Reply 599

hetty123

just some questions for you all (sorry if they've already been asked), i've tried to make sure they basically cover the whole section for F324 but i wasn't able to put in any calculation questions...

TOTAL MARKS= 58

what led scientists to doubt kekules model? [3marks]

compare using equations the difference in reactivity of Benzene and Phenol with a halogen? [6marks]

name the reagent, product and any colour change for the oxidation of the aldehyde 2-methylbutanal [3marks]

what is brady's reagent and what is its use? [3marks]

describe how you could make tollens reagent to detect an aldehyde in the laboratory [3marks]

use equations to show:
acid hydrolysis of propylethanoate [3marks]
alkali hydrolysis of propylethanoate [2marks]

why are aliphatic amines prepared via nucleophilic substitution of halogenoalkane with excess ammonia? [1mark]

what makes it possible for an amino acid to act as both an acid and a base? [1mark]

define what is meant by the term isoelectric point and zwitterion [2 marks]

what is meant by an optical isomer [2marks]

state 2 advantages of manufacturing pharmaceutical products to contain only one optical isomer, and describe 2 methods to do this by [4marks]

terylene is made from ethan-1,2-diol and benzene-1,4-dioic acid, write an equation for the production of terylene and draw a repeat unit [2marks]

what is the difference between addition polymers and condensaiton polymers? [2marks]

what are the pros of using biodegradable polymers and how can some condensation polymers photodegrade? [3marks]

what are the difficulties of synthesising a chiral molecule and describe 2 methods? [4marks]

describe what is involved with TLC and GC and their limitaions [7marks +1 for QWC]

what is the advantage of combining GC with MS and what can this be used for? [4 marks]

name the 2 requirements for NMR [2marks]

(i can't really ask you a proper Q on NMR really.....)