POST-EXAM CHAT: OCR Chemistry- Rings, Polymers and Analysis - F324 thread
Chemistry exam discussion - share revision tips in preparation for GCSE, A Level and other chemistry exams and discuss how they went afterwards.
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Re: POST-EXAM CHAT: OCR Chemistry- Rings, Polymers and Analysis - F324 threadBye.(Original post by chemguy)
I am a tutor in chemistry and also head of department at grammar school. Today I sat this examination paper and I was overwhelmed by the aura it emanated. As a result, I have now resigned from my post and intend to jump off from my first floor bedroom continuously until I bleed profously. Good day sir!
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Re: POST-EXAM CHAT: OCR Chemistry- Rings, Polymers and Analysis - F324 thread
for reagent A i put hcl cause would hydrolyse both the ester link and the amide links... this not correct?
for reagent C i put bromine, cause it would react with the phenol but not with the benzene ring of the first molecule... any thoughts on these? -
Re: POST-EXAM CHAT: OCR Chemistry- Rings, Polymers and Analysis - F324 threadlikewise(Original post by Sensory Scorpion)
Well for the amino acid sequence question i got something like valine...glycine..and leucine..i think. But im not to sure, i totally agree with dpd5 that the exam went fron nice to nasty!
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Re: POST-EXAM CHAT: OCR Chemistry- Rings, Polymers and Analysis - F324 thread
I don't think it was too bad really, pretty much what I expected, no particuarly nasty questions except the last one possibly as it was a bit open ended and didn't really prompt you with clues much.
Last edited by Josh-H; 27-01-2010 at 11:01. -
Re: POST-EXAM CHAT: OCR Chemistry- Rings, Polymers and Analysis - F324 threadwhy quote me for that lol(Original post by Josh-H)
I don't think it was too bad really, pretty much what I expected, no particuarly nasty questions except the last one possibly as it was a bit open ended and didn't really prompt you with clues much. -
Re: POST-EXAM CHAT: OCR Chemistry- Rings, Polymers and Analysis - F324 threadNow I realise that.lol.(Original post by desertwarrior)
there were 3 amino acids...
For the last question I thought it was talking about hydrolysis of amide links and ester links so I put HCL for B and NAOH for C.What products did everyone get? I got two products for each reaction...
I confusing myself.lol.
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Re: POST-EXAM CHAT: OCR Chemistry- Rings, Polymers and Analysis - F324 threadBut am i not right in saying both esters & amides can be hydrolysed using both acid and base... its just that amide is easier to do with alkali... so durely hydrolysis only works for reagent A (both of them)... please can someone confirm this?(Original post by Emmalouise1990)
Now I realise that.lol.
For the last question I thought it was talking about hydrolysis of amide links and ester links so I put HCL for B and NAOH for C.What products did everyone get? I got two products for each reaction...
I confusing myself.lol.
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Re: POST-EXAM CHAT: OCR Chemistry- Rings, Polymers and Analysis - F324 threadHCl isn't the reagent though, it's the catalyst used in hydrolysis. If you wanted to show hydrolysis you would've needed to put H2O.(Original post by adzharmer)
for reagent A i put hcl cause would hydrolyse both the ester link and the amide links... this not correct?
for reagent C i put bromine, cause it would react with the phenol but not with the benzene ring of the first molecule... any thoughts on these? -
Re: POST-EXAM CHAT: OCR Chemistry- Rings, Polymers and Analysis - F324 threadNo hydrolysis works for both of them, you can hydrolyse a peptide bond and an ester link. I don't know why people are talking about HCl and NaOH, they aren't the reagents in hydrolysis, they're the catalyst.(Original post by adzharmer)
But am i not right in saying both esters & amides can be hydrolysed using both acid and base... its just that amide is easier to do with alkali... so durely hydrolysis only works for reagent A (both of them)... please can someone confirm this? -
Re: POST-EXAM CHAT: OCR Chemistry- Rings, Polymers and Analysis - F324 thread
Er… it was 3 amino acids, but it was the same monomer unit. It just alternated up and down. It asked for the single monomer that it was made of, which was valine.
Unless I started imagining things halfway through the paper, which now worries me. -
Re: POST-EXAM CHAT: OCR Chemistry- Rings, Polymers and Analysis - F324 threadYour right! My mind just went blank...and I knew that amides hydrolse best with acids and esters hydrolyse best with alkalis so I jus guessed.(Original post by adzharmer)
But am i not right in saying both esters & amides can be hydrolysed using both acid and base... its just that amide is easier to do with alkali... so durely hydrolysis only works for reagent A (both of them)... please can someone confirm this?

so got that wrong.. ah welll only 2 marks hopefully still should have got an A