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Reply 1
does anyone have notes on Chromatography?
Hey could someone help me out here please:
my teacher is predicting me a C grade,
I got D's on f321 and f322 and a C on the practical
If a resit f322 and get a B and manage to get B's on both f324 and f325 and the practical
what will i get overall?
-thank you
Reply 3
I am also studying A2 chemistry. I didnt do very good but I think we should focus more of our attention on getting A"s and retake any of f321 or 2. A friend sugested using past paper cos examiners mark based on it. for example, there are millions of ways writing an answer but following how the mark scheme works would increase our chances of full marks hope to get in touch with u concerning yr next move and next of yr psa taking place, see ya.
Reply 4
I am also studying A2 chemistry. I didnt do very good but I think we should focus more of our attention on getting A"s and retake any of f321 or 2. A friend sugested using past paper cos examiners mark based on it. for example, there are millions of ways writing an answer but following how the mark scheme works would increase our chances of full marks hope to get in touch with u concerning yr next move and next of yr psa taking place, see ya.
Reply 5
has anyone started module 3 of unit 5? complex ions and ligands are very confusing :frown: (one teacher's working from the front, the other is working from the back so they meet in the middle kind of)
Reply 6
Original post by RachHill
has anyone started module 3 of unit 5? complex ions and ligands are very confusing :frown: (one teacher's working from the front, the other is working from the back so they meet in the middle kind of)


not yet, sorry! We're still on Module 4 and we have a long way to go (just finished Chromatography + Esters/Triglycerides)

I only know a little about ligands, so I won't be of any help :colonhash:

but maybe the Official Chemistry OCR book will be able to help? or Chem guide
Reply 7
we've barely finished aldehydes and ketones...i fear we are falling behind...
Reply 8
we're on the polymers unit i think.I got a C at AS,but now i've properly pulled my socks up in chemistry i actually love this unit,quite hard for those who don't revise but i actually remember a lot of things now.So so so much to remember though!
Hello, I was wondering if someone could help me get my head around azo dyes.

I don't really understand the mechanism behind the formation of the diazonium salt. What's the role of HNO2 and HCl?
Original post by motivatedshroom
Hello, I was wondering if someone could help me get my head around azo dyes.

I don't really understand the mechanism behind the formation of the diazonium salt. What's the role of HNO2 and HCl?


Phenylamine + HNO2 + HCL = DAIZONIUM SALT + WATER

Hope that's helped. The above is the Diaotisation stage
We haven't started f324 yet! Looks so boring! How are you guys finding it!

We have almost finished f325 stuff.


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Reply 12
doing some chemistry revision, stuck on this question, if anyone could help that will be great!:smile:

The recommended adult dose of chloral hydrate as a sedative is 250 mg, three times a day.
Calculate the mass of trichloroethanal you would need to react with water to make week's supply of chloral hydrrate for an adult, assuming a 60% yield.

Mr of chloral hydrate = 165.5
Mr of trichloroethanal: 147.5
I have some chemistry notes available in return for some rep ( me being cheeky) - basically they're PDF PowerPoints with every exam question and the corresponding answer from every paper since 2009( up to June 2012) for all units.Drop me a message if you want them and I'll send you them in return for some rep.P.s I did this for the guys on the f322 thread for jun 13's exam too and it went down well so holla at you guys :smile: :smile:


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Original post by letsbehonest
We haven't started f324 yet! Looks so boring! How are you guys finding it!

We have almost finished f325 stuff.


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How's F325 ? Is it as hard as everyone says it is ?


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Original post by krishkmistry
How's F325 ? Is it as hard as everyone says it is ?


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I am finding it quite hard but with practice it should be fine hopefully.
Got a f324 mock test on Thursday and I still dont know what to call the 'delocalised ring' in benzene:frown:!!!

Is it....

electrons in the 2p oribital of neighboring carbon atoms sideways overlap to produce a system of...

Pi bond or Pi electrons?!?!?! which one is it or help me find a better way to describe the delocalised model as its different in every book i read.
Original post by jamesfancourt
Got a f324 mock test on Thursday and I still dont know what to call the 'delocalised ring' in benzene:frown:!!!

Is it....

electrons in the 2p oribital of neighboring carbon atoms sideways overlap to produce a system of...

Pi bond or Pi electrons?!?!?! which one is it or help me find a better way to describe the delocalised model as its different in every book i read.



Well, in the official OCR Chemistry text book it says: " ..system of pi bonds which spread over all 6 carbon atoms." :smile:
Reply 18
has anyone got the june 2013 question paper by any chance?
due to popular demand,here are my chemistry exam q and a powerpoints,please rep me if you liked them and found them useful - thanks :smile: