AQA CHEM4 - 13th June 2012
Chemistry exam discussion - share revision tips in preparation for GCSE, A Level and other chemistry exams and discuss how they went afterwards.
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Re: AQA CHEM4 - 13th June 2012(Original post by Mero8)
Anyone know how to revise organic synthesis? I think it's going to make me kill myself
I'm just practicing questions... I think it's helping.
I really don't get proton nmr... like I understand the theory but then when I do the questions im lost ... aaaaaahhh -
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In the same position as you(Original post by Bright.Inspiration.)
I'm just practicing questions... I think it's helping.
I really don't get proton nmr... like I understand the theory but then when I do the questions im lost ... aaaaaahhh
the questions that make you 'identify' a molecule. I tend to struggle with, I always mess up the proton NMR Structure!
Last edited by Doctor.; 09-05-2012 at 22:30. -
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Re: AQA CHEM4 - 13th June 2012Can I just say a MASSIVE thanks for all the info. You have no idea how helpful it is!! Major thanks pal! Xxx(Original post by thegodofgod)
From what I know:
Warning: Answers in spoiler
Spoiler:Show
A1. +3 in hexahydroxochromate (III), +6 in tetraoxochromate (VI), (a.k.a. chromate (VI))
A2. Been oxidised, as it has lost 3 electrons.
B1. Primary / Secondary / Tertiary Alcohols
C1. Reduction.
C2. Become oxidised (remember, it is a redox reaction, so if something is reduced, something else must be oxidised).
C3. Tertiary alcohols, potassium dichromate (VI) is not a strong enough oxidising agent, or you can say that tertiary alcohols cannot be oxidised.
D1. Isomers must be tertiary alcohols, as they cannot be oxidised by potassium dichromate (VI): 2-methylpentan-2-ol; 3-methylpentan-3-ol; 2,3-dimethylbutan-2-ol. -
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Re: AQA CHEM4 - 13th June 2012Lol I just end up drawing random molecules and counting the hydrogens, and then realising i've done it wrong... :|(Original post by Doctor.)
In the same position as you the questions that make you 'identify' a molecule. I tend to struggle with, I always mess up the proton NMR Structure!
I think its the worst topic -
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Re: AQA CHEM4 - 13th June 2012I can't do this either!(Original post by Doctor.)
In the same position as you the questions that make you 'identify' a molecule. I tend to struggle with, I always mess up the proton NMR Structure!
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Re: AQA CHEM4 - 13th June 2012Really need to start revising this again lol! it's been days since I revised it last
how is everyone doing?
i'm assuming you're all busy with other exam revision?
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Re: AQA CHEM4 - 13th June 2012I had a Bio retake on Monday so been revising for that and also quite a bit for the June exam... not a lot of Chem :\(Original post by Doctor.)
Really need to start revising this again lol! it's been days since I revised it last
how is everyone doing?
i'm assuming you're all busy with other exam revision?
Going to get back to it today, as have the mock on Friday (Jan 2012 paper, trying to stop myself from looking!)
4 weeks today
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I've not been focusing much on CHEM4 either(Original post by skylight17)
I had a Bio retake on Monday so been revising for that and also quite a bit for the June exam... not a lot of Chem :\
Going to get back to it today, as have the mock on Friday (Jan 2012 paper, trying to stop myself from looking!)
4 weeks today
Other exams 
I've already done the Jan'12 paper, but made sure I got rid of the paper so hopefully I will forget the questions 
I can't revise any chemistry till my final AS resit is over its on the 26th so annoying!
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Re: AQA CHEM4 - 13th June 2012(Original post by Doctor.)
Really need to start revising this again lol! it's been days since I revised it last
how is everyone doing?
i'm assuming you're all busy with other exam revision?
I understand most of chem4 but some of the questions throw me off a bit :/
Did anyone do the chem1 retake ? -
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Re: AQA CHEM4 - 13th June 2012Quite a few people I know did, they found it a weird paper on the whole. Also I did go through the paper, seemed a little odd especially the hard concentration working out one(Original post by Bright.Inspiration.)
I understand most of chem4 but some of the questions throw me off a bit :/
Did anyone do the chem1 retake ?
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Re: AQA CHEM4 - 13th June 2012Weird is a good word to describe it.. There were no definitions etc aswell..(Original post by Doctor.)
Quite a few people I know did, they found it a weird paper on the whole. Also I did go through the paper, seemed a little odd especially the hard concentration working out one
On that conc question I forgot to dive the number by 5 so I must have lost like 2 marks there alone fml. Made some silly mistakes but hoping for over 90ums .. Optimism is the way lol -
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Exactly that! I think they're going to try make us apply the content much more though. Which isn't bad I guess, just hopefully they wont try and give trick question(Original post by callmenighthawk)
This paper is damn hard. Damn hard indeed. How has everyone been revising, from the book + past papers? That's what I've been doing.
I'm sure you've done fine(Original post by Bright.Inspiration.)
Weird is a good word to describe it.. There were no definitions etc aswell..
On that conc question I forgot to dive the number by 5 so I must have lost like 2 marks there alone fml. Made some silly mistakes but hoping for over 90ums .. Optimism is the way lol
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Re: AQA CHEM4 - 13th June 2012Definitely, I too have retaken the unit 1 exam on the 15th (and embarrassingly in January, too(Original post by Doctor.)
Exactly that! I think they're going to try make us apply the content much more though. Which isn't bad I guess, just hopefully they wont try and give trick question
) and both have required more apply content & thinking rather than stuff straight out the textbook - which is good if you actually know your stuff.
to whoever was asking about the moles question I also messed that up, times'd it by 1/7, but I think I knew virtually everything else and probably dropped 7 marks maximum, high 80s UMS probably, hopefully 90
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My teacher has made a pack of 60 questions for unit 4 which I'm currently going through which helps. -
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Re: AQA CHEM4 - 13th June 2012I've resat CHEM1 far too many times(Original post by callmenighthawk)
Definitely, I too have retaken the unit 1 exam on the 15th (and embarrassingly in January, too) and both have required more apply content & thinking rather than stuff straight out the textbook - which is good if you actually know your stuff.
to whoever was asking about the moles question I also messed that up, times'd it by 1/7, but I think I knew virtually everything else and probably dropped 7 marks maximum, high 80s UMS probably, hopefully 90.
My teacher has made a pack of 60 questions for unit 4 which I'm currently going through which helps.
Never again 
I think they're going to do a lot of the Equlibria & Kinetics but make us apply it Which isn't fun as it's just one of them topics where you think you know it...but then you don't know it lol
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Re: AQA CHEM4 - 13th June 2012Haha true that, in the empa where the slowest step was the first reaction I put the rate-determining step as the second step(Original post by Doctor.)
I've resat CHEM1 far too many times Never again
I think they're going to do a lot of the Equlibria & Kinetics but make us apply it Which isn't fun as it's just one of them topics where you think you know it...but then you don't know it lol
- so I've made an effort to try and understand it more.
I found buffer solutions & pH quite hard, but once you think of things in term of H+... it's pretty easy. for example
Ka = H+ x weak acid salt
_____________________
Weak acid
H+ = Ka x Weak acid
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Weak acid salt
if a base is added, the pH is going to be slightly higher, so you want a smaller value for H+ (because it determines pH (conc does too)) so to get a smaller value you add the small conc of base to the salt and take it away from the weak acid.
this helped me understand the whole process better, by looking at the equation and mathematically figuring out what was going to happen -
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Re: AQA CHEM4 - 13th June 2012process better, by looking at the equation and mathematically figuring out what was going to happen[/QUOTE]
I think the pH, buffers and all of that isn't too bad. Just takes a little while to get your head around it oh and a TON of practice questions on it
The rate stuff is just so annoying Ergh Proton NMR, still now getting the full marks for it! 
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Re: AQA CHEM4 - 13th June 2012I'm not sure I fully understand the process so I will definitely go over it past papers and stuff more.
emf can be a bit tricky, but we use a method for "ROOR" for drawing the emf cell, reduced oxidised || oxidised reduced, still need to understand when to use a salt bridge and other things though.
Yeah proton NMR and CNMR can be tricky, especially CNMR for me. -
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Isn't EMF CHEM5?(Original post by callmenighthawk)
I'm not sure I fully understand the process so I will definitely go over it past papers and stuff more.
emf can be a bit tricky, but we use a method for "ROOR" for drawing the emf cell, reduced oxidised || oxidised reduced, still need to understand when to use a salt bridge and other things though.
Yeah proton NMR and CNMR can be tricky, especially CNMR for me. I've done Chem5 
What's PH5? Not seen that before(Original post by callmenighthawk)
Is there a PH5 topic? I think I'm weaker in PH5 in actual understanding the content.
the questions that make you 'identify' a molecule. I tend to struggle with, I always mess up the proton NMR Structure!
Other exams 
) and both have required more apply content & thinking rather than stuff straight out the textbook - which is good if you actually know your stuff. 
. 
