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OCR AS - Chemistry Unit F322 - Chains, energy and resource - REVISION!

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Reply 700

egypt305

Original post by Rassam

Easy paper, just forgot about tetrahedral :/
Boundaries should be around 74 for an A.

Your joking rite?!
that paper was hardddd - compared to the others
i reckon it can go down to 67 for an A

Reply 701

anil10100

Yeah, I got -1279. But then again, I had absolutely no idea how to calculate it, but just juggled the numbers about a bit. D:

Reply 702

KatsG

I didn't even work out what the ester was!! :frown:

I only worked out what compound x and y were! :frown:

How many marks do you think i've lost?

Reply 703

racheatworld

Original post by nereik6794

You can't use Methanol in alcoholic drinks. Otherwise you would be unable to find your way to the toilet in the morning to 'whitey' due to being blind.

That's why I didn't put it, and said just then alcohols from fermentation (ie: not pure methanol) are used in drinks. I put as feedstock.

Reply 704

anil10100

Original post by KatsG

I didn't even work out what the ester was!! :frown:

I only worked out what compound x and y were! :frown:

How many marks do you think i've lost?

I think it was probably 2-3 marks for identifying the ester because you weren't actually using the data given.

But more importantly did you get ethanol and propanoic acid as X and Y?

Reply 705

Joseppea

Original post by KatsG

I didn't even work out what the ester was!! :frown:

I only worked out what compound x and y were! :frown:

How many marks do you think i've lost?

Probably not many :smile:

There's probably like 3/4 marks for working out X, 3/4 for Y and then 1/2 for the ester. (+1 for QWC) :biggrin:

Reply 706

nereik6794

Original post by racheatworld

That's why I didn't put it, and said just then alcohols from fermentation (ie: not pure methanol) are used in drinks. I put as feedstock.

I wrote feedstock for cracking, absolute guess :tongue:

Reply 707

EternalDoom

That paper did not even test my whole potential in terms of all the revision i did for this unit.....at least it'll make A2 easy

Reply 708

TitchTheAntiHero

I feel some parts went DEAD well and others went badly,
for the use of methonal I put to make methylated spirits, how likely is that to be correct?
and I said atom economy was more important, what did everyone elose put for that?

Reply 709

KatsG

Original post by anil10100

I think it was probably 2-3 marks for identifying the ester because you weren't actually using the data given.

But more importantly did you get ethanol and propanoic acid as X and Y?

Yes I did! I'm such a douche clearly didn't properly read the question! I hope is only 2 marks i've lost :smile:

Reply 710

ChessMister

Original post by racheatworld

Ethyl propanoate is the correct answer.

oh cool can you send me the rest of your mark scheme?

Reply 711

Joseppea

That's alright we all tried our best :wink:

lol JK I WANT A MILLION UMS POINTS O_O

Reply 712

thefirstnotlastsamurai

Who wishes they had taken geography aswell so you could of actually answered those ****ing green chemistry questions.

Reply 713

SmithytheDrummer

I got positive 1200 and something :s-smilie:

It was formation you had to find but they gave you combustion so it was B-C=A and I got positive. The percentage yield I thought was less important as even if was low you could pass it through the fermenter many times so that it all got turned into ethanol.

Reply 714

anil10100

Anyone else put tetrahedral for the shape around the first carbon because of the four bonded regions, and then trigonal planar for the shape around the second carbon?
Though that question was a bit ridiculous considering it's Unit 2 but yeah..

Reply 715

little_lamb

Ooops...I put methanol is used to make cheap alcoholic drinks... :colondollar:

And in the book it says methanol is 'extremely toxic and ingestion of small quantities can lead to severe organ damage and death' :eek:

Maybe it wouldn't be such a good idea to make cheap alcohol from it then :biggrin:

Reply 716

SpringNicht

I screwed up on the last one, got ethanol and propanoic acid - then wrote propylethanoate!

God I'm thick.

Reply 717

Jankenstein

Methylated alcohol should fit, that's not for use as solvents or fuels. It prevents the use of industrially-produced alcohols as drinking alcohols. I also put in antifreeze :P