OCR Chemistry Chains,Rings&S 21 Jan Watch

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duffer
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Has anyone just done this exam? Wat did you think about it?
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Usman_Ali
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The exam was OK I think
The essay writing Q was really good
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cobra
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Easy, they just put loads of rings in to try and confuse people but i dont think it worked, all questions were straight forward without tricks, an no drawing of mechanisms.

Bring on transition metals and trends and patterns on friday
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jediknight007
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It was one of the easiest papers I have ever done. I have never felt so confident about doing well in a paper before. The only questions which I remembered I got wrong were the 'other method for identifying the product from 2,4DNP' and the 'why can't H2 act as a nucleophile'. Can't believe I forgot how to answer them!
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cobra
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This is gonna be bad in a way cos they will make the grade boundaries really high if loads of people do well
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D.O.A
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The exam as a whole was okay..some things I felt confident on..but it really didn't help with the 1st question...it was on mass spectrometry..okay I know this..but they asked a Q that made almost no-sense to me.

Took me a good few mins to figure out what it was asking.
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cobra
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If that was the one with multiple rings i think the examiners thought 'i know what we'll do, we'll try to confuse then with a multiple ring phenol, but it sooooo didnt work
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Stunt-101
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(Original post by cobra01977)
If that was the one with multiple rings i think the examiners thought 'i know what we'll do, we'll try to confuse then with a multiple ring phenol, but it sooooo didnt work

I reckon it was just one of those questions they ask just to see if people actually know their organic chemistry rather than set a difficult question but in the exam it went on to see other knowledge, just like an easy 2 mark intro - what functional groups are present.


Did n e 1 get 2.88g for the calculation

I divided 800 cm3 by 1000
then multiplied it by 0.015
then i think i got 0.012
then multiplied it by 240 to get the 2.88g of mass which was in the 800 cm3 solution
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cobra
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(Original post by Stunt-101)
I reckon it was just one of those questions they ask just to see if people actually know their organic chemistry rather than set a difficult question but in the exam it went on to see other knowledge, just like an easy 2 mark intro - what functional groups are present.


Did n e 1 get 2.88g for the calculation

I divided 800 cm3 by 1000
then multiplied it by 0.015
then i think i got 0.012
then multiplied it by 240 to get the 2.88g of mass which was in the 800 cm3 solution
Yes i did get that, after intially getting 28.8g cos i put it in my calclater wrong
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George-W-Duck
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(Original post by cobra01977)
Yes i did get that, after intially getting 28.8g cos i put it in my calclater wrong
i got 2.88 too, i thought the exam was good, but like cobra says, there wont be any upgrade in the UMS so scores wont be increased (they cant however reduce your score, if they set an easy exam, it gets investigated but theyre not allowed to knock scores down ala 2001)
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equili3rium
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#11
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I question 1 there was this question of determining the structure of ketone A, but no spectroscopy. and using the product from adding 2,4 DNPH to the ketone.

my ans: the product from reaction of 2,4 DNPH and A produces water as a side product, and this can be used to determine the structure of the molecule by the depth of solubility ie globular or branched

I thought this was pretty neat question---if i got it correct

But dunno if it is.

Is it?
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jediknight007
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(Original post by equili3rium)
I question 1 there was this question of determining the structure of ketone A, but no spectroscopy. and using the product from adding 2,4 DNPH to the ketone.

my ans: the product from reaction of 2,4 DNPH and A produces water as a side product, and this can be used to determine the structure of the molecule by the depth of solubility ie globular or branched

I thought this was pretty neat question---if i got it correct

But dunno if it is.

Is it?
I believe that you can actually recrystallise the product and heat it up to determine it's melting point. By doing that, you can then find out what compound it is.

(Original post by Stunt-101)
Did n e 1 get 2.88g for the calculation

I divided 800 cm3 by 1000
then multiplied it by 0.015
then i think i got 0.012
then multiplied it by 240 to get the 2.88g of mass which was in the 800 cm3 solution
Yea, I got that as well but only after I went through my answers with 2 minutes to go! I initially used n=C/V when in fact it was C=n/V and therefore, the number of moles was the volume (in dm^3) multiplied by the concentration! Thank God for that!

The longer questions were so easy as well, especially the addition and condensation polymerisation one. I also think that the 2-mark questions such as identfying the 2 functional groups or drawing the 2 monomers were stupid questions. Oh well, another 4 easy marks there then!
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equili3rium
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but i thought the question asks the structure, cause we already know that its a ketone and it says using the product of the previous reaction
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equili3rium
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and there was a question on hydrolysis of esters, was it acid or alkali hydrolysis or either?

I did acid, what did u put?
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ThunderCat8
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I found this exam to be very much to my liking! It had all nice questions and nothing I couldn't do. There were a few odd questions that I bullshtted, like the one asking why Hydrogen can't be a nucleophile, but on the whole I think I did pretty well. Should at least get a B, hopefully an A, but I don't want to be too confident!!

I just wish that the Biology exam had been as nice as the Chemistry was, but ho hum, it wasn't!! DOH!
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*skye*
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hey,

in that case, i must be the only one then cos i didnt particularly like the paper. I opened it and cudav cried! I did actually revise tho and had learnt all the mechanisms and everything, but i got a bit confused with some reagents and conditions (always my downfall) and had to take an educated guess... as did with some of the equations cos my mental block had set in... eek. I hated the essay questions too! I hardly wrote anything for them! And so, im pretty sure i failed it! and it dusnt reassure me that u guys found it easy as did probably the rest of the country! The ppl at my school who did the exam were practically laughing at how simple it was....
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jediknight007
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(Original post by equili3rium)
and there was a question on hydrolysis of esters, was it acid or alkali hydrolysis or either?

I did acid, what did u put?
I believe that it was an acid because if you use a base to hydrolyse an ester, you get a sodium salt (if you are using NaOH) plus the alcohol instead of the usual carboxylic acid and alcohol with an acid.
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madmazda86
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That paper was fantastic I'm so so glad that I actually bothered to revise the Spectroscopy section as I'd completely forgotten how to do mass spectra.

What was the deal with the question on addition polymerisation where you had to draw the monomer? The resulting polymer had a flippin' ester linkage in it which completely threw me. I drew an aldehyde as the monomer but I have no idea whether that was right or not...
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Emz
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#19
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If it was an ester linkage then the monomers should be a (di)carboxylic acid and an (di)alcohol.....well I hope...
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cobra
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(Original post by Emz)
If it was an ester linkage then the monomers should be a (di)carboxylic acid and an (di)alcohol.....well I hope...
Yes ur right it was, he was wrong it wasnt an addition polymer and definatly wasnt a aldehyde
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