OCR A2 Chains, Rings &amp; Spectroscopy

ohh yeah just read, 'Of the twenty amino acids only glycine does not have a chiral centre'

Reply 21

the very part of the last question... a triplet between 1.2 and 1.4 with area 1, though i am not sure the area needed to be specified...

Reply 22

El Stevo

the very part of the last question... a triplet between 1.2 and 1.4 with area 1, though i am not sure the area needed to be specified...

I didnt think that the nmr question was that hard at all! It was quite resonable.

Reply 23

it is probably the first nmr question i have ever got right... i was away we did the whole spec/nmr thing...

Reply 24

Wat did people put about the important of nitration of benzene?
I put formation of azo dyes and formation of the polymer poly(nitrobezene) - couldnt think of anything else!
Is the formation of the explosive TNT done by nitration or Friedal Crafts?

Reply 25

Just looked on the sylabus. It says:

understand that reactions of arenes, such as those in (b), are used by industry during
the synthesis of commercially important materials, for example: explosives,
pharmaceuticals and dyes (from nitration).

I hope they let me have poly(nitrobenzene)

Reply 26

i think i put explosives and paint, azo dyes being used in paints... i didn't know ploynitrobenzene was that important a polymer, for example poly[chloroethene]

Reply 27

jeez, what an exam!

i have to say that i didnt do as good as i thought- especially the question on deducing the amount of electrons in the two rings- i just 4got how to work it out!

my savour was the bit on azo-dyes though! :smile:

Reply 28

back to the polymerisation question... i said addition, and the monomer was erm... i could draw it... it was like ethene but with one of the H replaced with a benzene ring...

Reply 29

I still so confused about the phenol and amine question! Wat did u have to do?

Reply 30

rainjan_4now

That question was HORRIBLE and totally left it out! I felt it was quite hard! It was too much for 5 marks!

Reply 31

El Stevo

back to the polymerisation question... i said addition, and the monomer was erm... i could draw it... it was like ethene but with one of the H replaced with a benzene ring...

phenylethene

Reply 32

froggymills

phenylethene

thats the one!

Reply 33

Please please please please tell me!
For the azo dye question at the bottom of the page did u only have to draw phenol and phenylamine??

Reply 34

froggymills

That question was HORRIBLE and totally left it out! I felt it was quite hard! It was too much for 5 marks!

for myself it was easy because i really concentrated revising it, but i got stupid questions wrong, like being unable to explain the peak around 3ppm of the nmr spectrum.

i hope everyone drew the 2nd isomer (the one with the methyl group) in the box. if not i am *****D!

last question was alright- i basically learnt about d20 on the bus to college!!

Reply 35

froggymills

That question was HORRIBLE and totally left it out! I felt it was quite hard! It was too much for 5 marks!

we'd done the prac at the beginning of the year, so i was trying to regurgitate that... making nitrous acid, reacting all under 10 degrees (in the prac i hit 40 :s-smilie:

) and then adding sodium nitrite i think...

Reply 36

froggymills

Please please please please tell me!
For the azo dye question at the bottom of the page did u only have to draw phenol and phenylamine??

that what i did! :confused:

but with a N2+CL- GROUP ON THE AMIDE

Reply 37

mistry

hey i did that paper.... know what u mean when it was odd because there were no "draw a mechansim for this" or many reaction question etc. What did u get for the materials that nitrobezene is used for. Also for the pi pond question i put 12 and 11.. y is it 6.... well atleast its over now

Reply 38

mistry

i really *****d up that question! :mad:

Reply 39