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OCR A2 CHEMISTRY F324 and F325- 14th and 22nd June 2016- OFFICIAL THREAD

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Original post by anonymous_veg
For the impurity, I had 2 propanols joined by their second carbon to an NH, linking them, does that seem right?


Yes got the same thing
Original post by wer34576
pretty sure it was 3. 2 from the non glycine amino acids and 1 on the third amino acids side chain(think this is the 3rd amino acid in the table-cant remember name though).

actualy i can remember the side chain(R) had a h a CH3 and a CH2CH3


weu4gifbaeiruw THANK U KIND SIR

isoleucine was the 3rd amino acid, hence its R-Group contains yet another chiral carbon.
Original post by sfarquhar0
Maybe 4-5 ? I got F wrong also dw


i also got F wrong. I got H correct but because I got F wrong it meant that I got G and I wrong aswell :frown: just hoping the examiners will allow ECF
For the question about synthetic vs fermentation, do i have to state that synthetic produces TWO optical isomers?
I just said that synthetic produces a mix of isomers where as the fermentation only produces one.
Also, with the lactic acid dissolving, i only mentioned the OH from COOH Forming H bonds! I completely lost sight of the other OH group. Is this a mark lost? :frown:
I felt so confident... coming on here wasnt a good idea!


Dont want to seem like a ****, but OCR have pretty much never put 8 marks between grade boundaries, possibly your A* is too high? was thinking maybe 56/57 for full UMS and 52/53 for A*?
Original post by RetroSpectro
Yes got the same thing


Yeah boi!
Original post by abhula
yh hopefully! they're always pretty good with ecf and you'll make up the marks elsewhere!


I upset now :C i knew id make stupid mistakes
I put ranges of chemical shifts on the proton nmr table instead of single values, would I lose any marks?
3 chiral carbons not including glycine on the tripeptide
Original post by skyaviator23
Dont want to seem like a ****, but OCR have pretty much never put 8 marks between grade boundaries, possibly your A* is too high? was thinking maybe 56/57 for full UMS and 52/53 for A*?


If those were the boundaries then 50 would be an A* and 54 would be full. The difference between each grade is always the same.
Original post by skyaviator23
Dont want to seem like a ****, but OCR have pretty much never put 8 marks between grade boundaries, possibly your A* is too high? was thinking maybe 56/57 for full UMS and 52/53 for A*?


maybe lower for an A* then but the rest seems resonable ...i hope so anyway
(edited 7 years ago)
guys, I put 2-hydroxycarboxylic acid for the systematic name will i lose a mark?
Original post by skyaviator23
Dont want to seem like a ****, but OCR have pretty much never put 8 marks between grade boundaries, possibly your A* is too high? was thinking maybe 56/57 for full UMS and 52/53 for A*?


nah, i analysed the jan 2013 paper, 90% identical to our 2016 paper.


It will realistically be:

59; MAX
55; A*
51; A
47: B
43; C

PS; this is jan 2013's boundaries :P
Reply 2133
Original post by Sahil_
I put ranges of chemical shifts on the proton nmr table instead of single values, would I lose any marks?


If you quoted the exact range possible, you'd get the marks I'd say
For the chromatography question, is the answer not;
Similar compounds will appear in the same spot on the chromatography plate
This is because they have similar physical properties e.g. volatility, adsorption to stationery phase, solubility in mobile phase
The similar physical properties are caused by similar molecular structures and similar functional groups in the molecular structure
Original post by 24u5owehjr34uoer
nah, i analysed the jan 2013 paper, 90% identical to our 2016 paper.


It will realistically be:

59; MAX
55; A*
51; A
47: B
43; C

PS; this is jan 2013's boundaries :P



If i was a betting man, A will no doubt be 50+/60
anyone have an unofficial mark scheme?
Reply 2137
Original post by jadder1224
guys, I put 2-hydroxycarboxylic acid for the systematic name will i lose a mark?


It was 2-hydroxypropanoic acid, so yeah, lost that one I'm afraid
Reply 2138
Any decent unofficial mark scheme?
IMG_3327.jpg
Points (5) and (7) : does this mean you could actually have chosen any of the fatty acids, as long as you justified it correctly?

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