LAST MINUTE QUESTIONS <3

[crayolé]

Okay, well I've got about 10 exams to go through today so it would be very much appreciated if you guys could answer some questions for me along the way <3
Sorry for spamming up the board so much :/

Okay, So first up, why isnt the bottom right box '1'?

[Studyinghard]

The connecting atom to the CH3 is Oxygen. therfore no splitting. basically same reason why the box above is 0.

[azndevo0l]

the carbon adjacent to it does not have a hydrogen

[Nomvalt]

Did you just answer that question too quickly? I just did that exam and made the same silly mistake!

[crayolé]

Yeah but the other answers on the bottom row state the number of peaks you'd see for each carbon, wouldnt the circled hydrogen have one peak then?

[Studyinghard]

Im not sure what you mean by that statement but il try and explain.

Firstly this is hydrogen NMR therefore nothing to do with carbons.

The CH3 on the far left breaks into 3 because of the adjacent carbon that has 2 hydrogens. The CH2 breaks into 4 because the adjacent has 3. Now the CH3 on the far right cannot break into any because the adjacent has no hydrogens.

Hope that helped

[azndevo0l]

this is splitting not peaks

[crayolé]

Ah I see thanks very muchly ;], so will there be no peak for those hydrogens then?

I was looking at it as if the first one splits into three observable peaks, the second one will split into 4, the last one would split into one observable peak

Thanks!

[Mao]

There will be one peak, but no splitting. You are getting caught on the semantics. The question asks for the 'number of splits', but since there is no splitting (it comes out as a singlet), this is 0. If the question asked for 'number of peaks', it will be 1.

An analogy is if there are two children in a family, there are 2 siblings. If there is only one kid, however, there are no siblings.

[crayolé]

Cheers Mao, <3

Q: Do we have to know structures of Paracetamol, Salacylic acid/Aspirin and hey they're manufactured?

[Studyinghard]

You will need to know how they are manufactured, only aspirin, which is obviously salacylic acid plus acetic anhydride but not the specific structure of them.

[chansthename]

You will need to know how they are manufactured, only aspirin, which is obviously salacylic acid plus acetic anhydride but not the specific structure of them.

or ethanoic acid

[masonnnn]

You will need to know how they are manufactured, only aspirin, which is obviously salacylic acid plus acetic anhydride but not the specific structure of them.

or ethanoic acid

regarding that, if it's with ethanoic acid instead of acetic anyhydride, is the disadvantage it's slow yet advantage that the overall % yield is greater?
or is acetic anyhydride's yield greater ie, ethanoic acid just... useless.
probably end up having no question to do with it but better to be safe than sorry?

[Studyinghard]

acetic anhydride is greater yield and also quicker reaction.

[masonnnn]

this is good,  thanks