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

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Original post by MrZebraCookie
For the fats question, would the answer be that the one with two double bonds have a higher probability of forming transfats?


I said that the first one was saturated since it had no double bonds, therefore it was a bigger risk.

1.

As they specifically specified HCL, you had to write NH3 Cl or NH3+ Cl-...

I knew a lot of people would miss that out.

damn and to think I thought I was slick for remembering to put NH3+
Original post by mil88
Incorrect


Why incorrect? In the presence of an acid, amine groups accept H+ in an equilibrium reaction to reduce the acidity
Usually they allow either nh3+ or nh3+cl- right?
Original post by Yazmin123
yeah exactly!
What was the answer to first question? I said the one with the 2 double bonds, as it could be in trans configuration which contributes to heart disease.
:s-smilie:
Original post by k.russell

1.

As they specifically specified HCL, you had to write NH3 Cl or NH3+ Cl-...

I knew a lot of people would miss that out.

damn and to think I thought I was slick for remembering to put NH3+


Indeed, a very similar principle to this has been tested before and I learnt the hard way.
Original post by Kkavina
It was a double, multiplet and doublet for the splitting pattern


i got quartet for the last one
Original post by callmesra
Grade Boundary predictions?


52 for an A??
Inbox me your answers for the questions you remember and I'll put together an unofficial mark scheme?
Hi guys ,could any of you remember what each question was roughly on please I forgot to check if any of my pages were stuck together and go through my paper so I'm really panicking if I missed a whole question out . Thank you :smile:
Would you be allowed Propan-2-ol-1-oic acid instead of 2 hydroxyl propanoic acid?
Reply 1791
Avatar for niiaw
niiaw
1
for the chromatogram, did anyone have points like : calculate Rf values, compare it to a database, and similar amino acids have similar rf values,so only two spots are shown?
Original post by NervousBoy
Inbox me your answers for the questions you remember and I'll put together an unofficial mark scheme?


you could create a google docs??
Answers for the NMR table? as in the chemical shift values haha
Original post by ali_t9001
Why incorrect? In the presence of an acid, amine groups accept H+ in an equilibrium reaction to reduce the acidity


If it just stated 'acid hydrolysis', then you're correct. However, stating HCL is specific, and thus you're expected to realise amines react with such acids to form salts, not ions.
Original post by KB_97
image.jpeg

I got this for the last question. Compound J I think. Anybody else get this?


yes this is exactly what i got
Original post by mil88
As they specifically specified HCL, you had to write NH3 Cl or NH3+ Cl-...

I knew a lot of people would miss that out.


i still think nh3+ is correct
Original post by Magicalgeofray
you could create a google docs??


https://docs.google.com/document/d/1sJ1zRjH6XZ0MwCAI7JIVbP_WobX4JL2jcdvYh3NHFKs/edit Try this, inbox me if you want to be admin and feel you confidently know most of the answers
Well I think it depends on the specific wording because if it says 'which COMPOUND is formed' then NH3+ is a lost mark bc it's an ion not a compound, however if I remember correctly, it just asked for the products? So if it's products then NH3+ is probs ok..
Original post by KB_97
Usually they allow either nh3+ or nh3+cl- right?


If they left it ambiguous, then you're correct. However, this isn't the case.

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