ATAR Notes: Forum

VCE Stuff => VCE Science => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Chemistry => Topic started by: Stroodle on May 21, 2010, 08:21:06 pm

Title: Stroodle's Questions
Post by: Stroodle on May 21, 2010, 08:21:06 pm

In H NMR, what's a multiplet?

And which company makes the hardest trial exams? Are there any companies that make their exams harder than the VCAA ones?

Cheers.

Title: Re: Stroodle's Questions
Post by: physics on May 21, 2010, 09:18:39 pm

multiplet is like a lot of peaks like 7 splits at a H for example. lol . it was on the trail exam.

Title: Re: Stroodle's Questions
Post by: Stroodle on May 21, 2010, 09:32:00 pm

Yeah, I know; STAV 2010. Was wondering how many peaks/splits though..

Title: Re: Stroodle's Questions
Post by: physics on May 21, 2010, 09:33:27 pm

Quote from: Stroodle on May 21, 2010, 09:32:00 pm

Yeah, I know; STAV 2010. Was wondering how many peaks/splits though..

yeh that. the answer is wrong .btw

Title: Re: Stroodle's Questions
Post by: Stroodle on May 21, 2010, 10:01:02 pm

Really? What's the answer then? I got the same answer as them, but only cause I picked the molecule with the most splits...

Title: Re: Stroodle's Questions
Post by: physics on May 21, 2010, 10:09:23 pm

wait i think it was same question but the last part of it :P when they ask for the number of peaks hah

Title: Re: Stroodle's Questions
Post by: Stroodle on May 21, 2010, 11:08:58 pm

Oh ok, cool. One extra mark for me somewhere then :)

Does anyone know the difference between the old chem course and the new one? I just did the 2004 exam, and noticed there was equilibrium and industrial chem in it. Is there anything else?

Title: Re: Stroodle's Questions
Post by: fady_22 on May 22, 2010, 07:28:08 pm

Quote from: Stroodle on May 21, 2010, 11:08:58 pm

Oh ok, cool. One extra mark for me somewhere then :)

Does anyone know the difference between the old chem course and the new one? I just did the 2004 exam, and noticed there was equilibrium and industrial chem in it. Is there anything else?

There isn't any of the biomolecules stuff in unit 3 of the old course, which used to be called "food chemistry" and was in unit 4.

Title: Re: Stroodle's Questions
Post by: Stroodle on May 22, 2010, 10:50:57 pm

ok, cool. thx

Title: Re: Stroodle's Questions
Post by: vexx on May 22, 2010, 10:54:12 pm

Quote from: Stroodle on May 21, 2010, 09:32:00 pm

Yeah, I know; STAV 2010. Was wondering how many peaks/splits though..

i read somewhere that a multiplet peak is one that is 5+ splits, but usually these splits have their own names 'quintet' but also referred to as multiplets. we don't have to know this exact split number though :|

Title: Re: Stroodle's Questions
Post by: Mao on May 22, 2010, 11:16:03 pm

All replies re: multiplets are incorrect.

Multiplets are when two (or more) sets of distinct peaks overlap and it becomes difficult (or even impossible) to distinguish the different sets, and it is impossible to assign splitting patterns such as 'quintet' or 'sextet' to the environments.

This happens when more than one environments have very similar surroundings, such as the 4th and 5th carbon on hexan-1-ol.

Title: Re: Stroodle's Questions
Post by: vexx on May 23, 2010, 02:41:31 am

Quote from: Mao on May 22, 2010, 11:16:03 pm

All replies re: multiplets are incorrect.

Multiplets are when two (or more) sets of distinct peaks overlap and it becomes difficult (or even impossible) to distinguish the different sets, and it is impossible to assign splitting patterns such as 'quintet' or 'sextet' to the environments.

This happens when more than one environments have very similar surroundings, such as the 4th and 5th carbon on hexan-1-ol.

Maybe it's fine for vce chemistry, because the notes i have say
"3 peaks is called a triplet. 4 peaks is called quartet. More complex peak clusters may be referred to as multiplets"
Or is this definitely wrong?><

Title: Re: Stroodle's Questions
Post by: Mao on May 23, 2010, 04:18:36 am

I see your point, and there really isn't a clear answer to this.. At All.

Title: Re: Stroodle's Questions
Post by: Stroodle on May 23, 2010, 09:42:11 am

Awesome. Thanks for the info guys.