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

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Even though a lot of people on here say that it went really well, people who found it really hard aren't going to broadcast it. Definitely do not think an A will be above 50/60 as there are always those who struggle and bring averages etc down.

Reply 1801

FluffyCommie

Original post by greenorange

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:

I'm pretty sure it was the first one, due to the fact that it was a saturated fatty acid whose molecules could pack tightly together. which would contribute to the build up of LDL cholesterol, which is a risk factor in heart disease

Reply 1802

username2221225

Original post by Bubbleszz

Answers for the NMR table? as in the chemical shift values haha

I put 1.2 ppm
2.6 ppm
3.6 ppm

Reply 1803

bulkybros100

For the triglyceride, would they allow if you drew the ester of glycerol but then used -C17H28 or whatever it was as the fatty acid tail instead of the structural (CH2)(CH3) ??

Reply 1804

chanda01

Original post by chanda01

For the last question, if you get F wrong, you get G and I wrong too right? Meaning forgetting the methyl group and hence putting down a straight chain since G had 4 carbon environments so F would have had to had the methyl group? In this case, would you get 3/4 marks as you got F wrong, but G and I would be ecf? or would you just get 1/4 because you got F wrong hence G and I too?

anyone...?

Reply 1805

MrZebraCookie

Original post by dairychocolate

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

But the book says that trans fats behave like saturated fats in the body idek

Reply 1806

ahamathslols

Original post by Derek12353

yes this is exactly what i got

This is wrong as it wouldn't oxidise to a a ketone

Reply 1807

Kvothe the Arcane

Original post by EricPiphany

Questionable, it was nylon not Kevlar. But I don't really know.

I put clothing fibre.

Feel I got 55-59/60

Reply 1808

Dentistry101

Original post by k.russell

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+

I reckon nh3+ will be in the allowed column

Reply 1809

username2097061

Original post by Yazmin123

i still think nh3+ is correct

What you think is your choice, I'm not here to argue that I am correct etc

I've learnt the hard way from this, and thus I remembered in the exam. My point is, this test was fairly straightforward but there were many chances to make mistakes, this being one of them.

Reply 1810

Magicalgeofray

Google docs mark scheme, please be responsible when adding answers and i will make admins the best contributors: https://docs.google.com/document/d/1sJ1zRjH6XZ0MwCAI7JIVbP_WobX4JL2jcdvYh3NHFKs/edit

Reply 1811

Bubbleszz

Original post by greenorange

I put 1.2 ppm
2.6 ppm
3.6 ppm

yey I did the same thing :smile:

but i did 2.7 :wink:

haha

Reply 1812

jonnypdot

for the hydrolysis of amide question i had a acyl chloride drawn instead of a carboxylic acid because it said dilute HCl not aqueous i dont know tho.

Reply 1813

SazahSauce

Original post by izaa29

For the percentage yield question I got something like 7.26 g

Omds I feel like I'm the only one who failed this paper

It was easy but I made so many silly mistakes :frown:

I'm so upset now

dw same here, so disappointed...

Reply 1814

jirapat121

Original post by MrZebraCookie

But the book says that trans fats behave like saturated fats in the body idek

but the other could be either cis or trans it's just have double bonds so the first one is the correct one

Reply 1815

TheDimpleboy

Think I'm the only that got 2.56 for the mass where you were given the percentage yield lol, looks like the right answer is 2.66. I must have made an mr error but hopefully I'll still get 2 working marks.

Also I said Kevlar for the polyamide question, but I don't think I'll get the mark, clothing fibres is what I should have put.

Other than that; the paper was a lot nicer than last years.

Reply 1816

FluffyCommie

Original post by Kvothe the arcane

I put clothing fibre.

Feel I got 55-59/60

I put clothing as its use, do you think that will be sufficient?

Reply 1817

lai812matthew

I think this paper is harder than last years there are a lot of word questions like the first one and the PLA one I don't know what is going on. would rather preferred complex reactions and mechanisms, or nmrs then this