OCR Chemistry A F322 Chains, Energy and Resources Wed 23 May 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: OCR Chemistry A F322 Chains, Energy and Resources Wed 23 May 2012I know the feeling! But exam papers are the best way to boost your grade. I currently have 15 or so sitting on my desk that I'm hoping to complete by the end of this week XD(Original post by Stir fried Giblets)
Thought it was going well, then I started doing a past paper so: ****
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Re: OCR Chemistry A F322 Chains, Energy and Resources Wed 23 May 2012Tried it, then went up by 10 marks but still didn't go up a grade(Original post by mmasters)
I know the feeling! But exam papers are the best way to boost your grade. I currently have 15 or so sitting on my desk that I'm hoping to complete by the end of this week XD
FML.
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Re: OCR Chemistry A F322 Chains, Energy and Resources Wed 23 May 2012
Hi everyone, I have made some past paper booklets on the topics in this unit, if anyone would like to have a collection that they could go through or focus on a specific topic
If you want a booklet on a more specific topic than the ones I've uploaded (as they may be a bit broad still) then don't hesitate to ask and I can make one. (I converted some to pdf to make the file small enough to upload in one piece)
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Re: OCR Chemistry A F322 Chains, Energy and Resources Wed 23 May 2012Nice good job I've been Savin up my printer credits to use on something like this(Original post by browb003)
Hi everyone, I have made some past paper booklets on the topics in this unit, if anyone would like to have a collection that they could go through or focus on a specific topic
If you want a booklet on a more specific topic than the ones I've uploaded (as they may be a bit broad still) then don't hesitate to ask and I can make one. (I converted some to pdf to make the file small enough to upload in one piece)
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Re: OCR Chemistry A F322 Chains, Energy and Resources Wed 23 May 2012You are awesome(Original post by browb003)
Hi everyone, I have made some past paper booklets on the topics in this unit, if anyone would like to have a collection that they could go through or focus on a specific topic
If you want a booklet on a more specific topic than the ones I've uploaded (as they may be a bit broad still) then don't hesitate to ask and I can make one. (I converted some to pdf to make the file small enough to upload in one piece)
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Re: OCR Chemistry A F322 Chains, Energy and Resources Wed 23 May 2012
Hey,
Could somebody help me with Dynamic equilibrium and just the basic concepts that maybe go with it? I kinda struggle a lot on them sort of Q's on past papers - did the Jan 2012 mock this week and I probably spent like 10 minutes or so on the Q in there!
I do sometimes understand it, I just get confused with all the effects temperature and pressure will have on equilibrium.
Thanks!
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Re: OCR Chemistry A F322 Chains, Energy and Resources Wed 23 May 2012A good idea would just be to learn using the mark-schemes rather than using the book, it tends to waffle sometimes and mentions points which arent accepted in the mark scheme thus over-complicating things and wasting your time.(Original post by Myda)
Hey,
Could somebody help me with Dynamic equilibrium and just the basic concepts that maybe go with it? I kinda struggle a lot on them sort of Q's on past papers - did the Jan 2012 mock this week and I probably spent like 10 minutes or so on the Q in there!
I do sometimes understand it, I just get confused with all the effects temperature and pressure will have on equilibrium.
Thanks!
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Re: OCR Chemistry A F322 Chains, Energy and Resources Wed 23 May 2012
From what I've found, this exam is very attention to detail.
Make sure you state where your double bond is... make sure you cover every point in the statement, and learn your definitions! Every year at least two have come up. The definitions that you need to know are:
Enthalpy Change of Reaction: The enthalpy change expressed in the molar quantities in a equation, with all reactants and products being in their standard states under standard conditions.
Enthalpy Change of Combustion: The enthalpy change that takes place when 1 mole of compound COMBUSTS (NOT BURNS) completely with oxygen under standard conditions, all reactants and products being in their standard states.
The Enthalpy Change of Formation: The enthalpy change that takes place when 1 mole of compound is formed from its constituent elements under standard conditions, all reactants and products being in their standard states.
Radical- Species with an unpaired electron
Electrophile- Electron pair acceptor
Nucleophile- Electron Pair Donor
Average Bond Enthalpy- The enthalpy change required to break by homolytic fission 1 mole of a given gaseous species.
Activation Energy- The minimum amount of energy required for the bonds to break in a reaction and for them to collide and react together.
Le Chatelieur Principle: For a reaction in Dynamic Equillibrium, if a change is made to the conditions (Pressure, Concentration, Temperature), the equillibrium will act in such a way to minimise this change
Functional Group- An atom/group of atoms responsible for the chemical properties of the compound and its reactions
Homologous Series: Group of Organic Molecules with the same functional group and each successive member differing by CH2
Empirical Formula: The simplest whole number ratio of atoms of each element present in a compound.
Molecular Formula: The actual number of atoms of each element present in a compound
Displayed Formula: Shows the atoms in a compound and the bonds located between them.
Skeletal Formula- Shows the minimal detail of a compound, by removing any additional atoms leaving only the carbon skeleton and any associated functional groups
Any More i've missed be sure to add them up
good luck everyone
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Re: OCR Chemistry A F322 Chains, Energy and Resources Wed 23 May 2012
This exam is consuming my life. I had a dream that a carbon atom and four hydrogen atoms (methane) were holding hands and dancing towards a chlorine radical. Then one of the hydrogen atoms let go of the carbon atom and began to hold hands with the chlorine radical. Now I don't think I'll ever forget that radical substitution mechanism.
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Re: OCR Chemistry A F322 Chains, Energy and Resources Wed 23 May 2012
I'm SO scared for this exam! I got an A in F321 (but only just) and I'm predicted an A overall but you need about 80% in this module! I'd be so happy even if I just managed to scrape an A but I'm finding this hard.
I know it's tricky explaining these sorts of things on here but I don't understand structural formula, like what do the brackets mean? How do you show a branch? Do you go by the longest chain and work from that? -
Re: OCR Chemistry A F322 Chains, Energy and Resources Wed 23 May 2012Only Alkenes can have E/Z isomerisation.(Original post by blue012)
Could anyone please help with E/Z isomerism. How do you know that your hydrocarbon can form this and do they always have to be functional groups of the double bonded carbon. ASAP PLS>
E is when groups are bonded to opposite sides of the double bond.
Z is when they bond to the same side.
Any question on this make sure you say CARBON CARBON double bond that CANNOT ROTATE.
Hope this helps
... Also, does anyone know what kind of raw mark is needed for 100% UMS?
Thanks
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Re: OCR Chemistry A F322 Chains, Energy and Resources Wed 23 May 2012It's impossible to say because the grade boundaries fluctuate so much. I would probably say that you'd be looking at around the 95+/100 mark for full UMS normally.(Original post by JohnSimmons)
Only Alkenes can have E/Z isomerisation.
E is when groups are bonded to opposite sides of the double bond.
Z is when they bond to the same side.
Any question on this make sure you say CARBON CARBON double bond that CANNOT ROTATE.
Hope this helps
... Also, does anyone know what kind of raw mark is needed for 100% UMS?
Thanks
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Re: OCR Chemistry A F322 Chains, Energy and Resources Wed 23 May 2012I dont think you need 80% for an A. Majority of papers I have seen, for the summer exams anyway, have requires 75-77% raw marks....anyone want to add me on facebook/msn and we can test each other and give pointers and how to improve answers/make them more concise. My fb name is the same as my name on here(Original post by thescientist17)
I'm SO scared for this exam! I got an A in F321 (but only just) and I'm predicted an A overall but you need about 80% in this module! I'd be so happy even if I just managed to scrape an A but I'm finding this hard.
I know it's tricky explaining these sorts of things on here but I don't understand structural formula, like what do the brackets mean? How do you show a branch? Do you go by the longest chain and work from that? -
Re: OCR Chemistry A F322 Chains, Energy and Resources Wed 23 May 2012Yeah I'm starting to see that now! Thanks for the advice.(Original post by adamcusirinzon)
A good idea would just be to learn using the mark-schemes rather than using the book, it tends to waffle sometimes and mentions points which arent accepted in the mark scheme thus over-complicating things and wasting your time.
You mentioned msn/fb, I wouldn't mind doing it! -
Re: OCR Chemistry A F322 Chains, Energy and Resources Wed 23 May 2012Well for January 2012 it's 83/100(Original post by adamcusirinzon)
I dont think you need 80% for an A. Majority of papers I have seen, for the summer exams anyway, have requires 75-77% raw marks....anyone want to add me on facebook/msn and we can test each other and give pointers and how to improve answers/make them more concise. My fb name is the same as my name on here
June 2011 was 76/100 though.
Message me your msn, haven't been on it for ages but I'll add you, could do with someone to test me/ help out!
FML.
If you want a booklet on a more specific topic than the ones I've uploaded (as they may be a bit broad still) then don't hesitate to ask and I can make one. (I converted some to pdf to make the file small enough to upload in one piece)
good luck everyone