OCR Chemistry A F324 Rings, Polymers and Analysis Tue 19 June 2012

hey guys can you please help me answer this? quick question?
okay, here we GOOOOOOOOO (wtf? cmon man lets hear the question):

when naming an ester does the alcohol go first or the carboxyllic acid? eg ethyl butanoate is that made of ethanol and butanoic acid or butanol and ethanoic acid?

Thanks

Reply 1381

arvin_infinity

3

Original post by ChrisJ

Waiiit, you're all right but it's always a gas mobile phase in GC. Should read:

'GC has 2 types solid stationary phase & gas mobile phase = adsorption ... '

Sorry if i've confused you a little, it's hard to get your head around :wink:

Not adsorption but partition or differences in solubility

Reply 1382

niaghez

Original post by seamen

4 aromatic and 1 normal so 5 peaks.

wait so how man C and H environments are there each?

Reply 1383

seamen

Original post by ChrisJ

I think it has 4
Hopefully the pic is ok..

oh thats proton NMR I thought it was carbon 13 NMR :redface:

Reply 1384

arvin_infinity

3

Original post by DonWorryJockIsHere

hey guys can you please help me answer this? quick question?
okay, here we GOOOOOOOOO (wtf? cmon man lets hear the question):

when naming an ester does the alcohol go first or the carboxyllic acid? eg ethyl butanoate is that made of ethanol and butanoic acid or butanol and ethanoic acid?

Thanks

ethanol ..

Reply 1385

ILikeToEat

So do alcohol groups react with NaOH to make O-Na+ or not?

Reply 1386

SmithytheDrummer

6

Original post by ChrisJ

I think it has 4
Hopefully the pic is ok..

If this is for Carbon environments then it has 5, not 4.

Reply 1387

ChrisJ

Original post by arvin_infinity

Not adsorption but partition or differences in solubility

For when it is a liquid stationary phase, yes, partition/solubility.

When you have a solid stationary phase, adsorption.
Right?

Reply 1388

seamen

Original post by niaghez

wait so how man C and H environments are there each?

Carbon NMR 5, and Proton NMR 4

Reply 1389

SmithytheDrummer

6

Original post by DonWorryJockIsHere

hey guys can you please help me answer this? quick question?
okay, here we GOOOOOOOOO (wtf? cmon man lets hear the question):

when naming an ester does the alcohol go first or the carboxyllic acid? eg ethyl butanoate is that made of ethanol and butanoic acid or butanol and ethanoic acid?

Thanks

First bit is alcohol, second bit is acid.

Reply 1390

beccihayes

can anyone explain to me how to how to determine the number of C/H environments in benzene?

Reply 1391

ChrisJ

Original post by SmithytheDrummer

If this is for Carbon environments then it has 5, not 4.

For hydrogen environments. Do you agree on the number of H environments?

Reply 1392

seamen

Original post by zhang599

Benzoic acid will give 5 peaks in C13 NMR and 3 peaks for Proton NMR.

4 peaks in proton NMR, 3 by CH in aromatic and last one in OH.

Reply 1393

clad in armour

16

Am I then to understand that a benzene ring ON ITS OWN has only one carbon and environment and 1 hydrogen environment therefore producing one peak in both

what about splitting?

Reply 1394

Squshy_Olorin

13

Original post by seamen

4 peaks in proton NMR, 3 by CH in aromatic and last one in OH.

Forgot about the OH lol xD

Reply 1395

SmithytheDrummer

6

Original post by ChrisJ

For hydrogen environments. Do you agree on the number of H environments?

Yes, that's right then :smile:

Reply 1396

user977153

Repost: http://0.tqn.com/d/chemistry/1/0/f/F/1/meta-xylene.jpg Can someone look at this molecule. Does it have 2 proton environments due to the benezne? My teacher said it was 2 because all protons directly attached to benzene are equivalent.

Reply 1397

seamen

Ok guys time to wish you good luck I am going to take a shower then Read through my notes 5 times then off to exam see you guys and good luck with the exam.

Reply 1398

Squshy_Olorin

13

Original post by DoctorVertigo

Repost: http://0.tqn.com/d/chemistry/1/0/f/F/1/meta-xylene.jpg Can someone look at this molecule. Does it have 2 proton environments due to the benezne? My teacher said it was 2 because all protons directly attached to benzene are equivalent.