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OCR A 2016 Chemistry A* A-Level Resources

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Is anybody else finding organic chemistry difficult? It's proving to be a pain in the backside for me
Original post by tcameron
Really struggling to understand Entropy
It's only 2 pages of the book and seems strightforward but when I tried past paper questions, I just couldn't understand


Don't think you need to understand it tbh. The questions were the same every year if I remember correctly.
Original post by gooner_hsj
Is anybody else finding organic chemistry difficult? It's proving to be a pain in the backside for me
Actually, the organic stuff might be my favourite part :tongue: Well... except when it comes to NMR questions in the exam :eek: Which bits do you find difficult?


Omg yes. The examples in my textbook are soft compared to that horror of a question on that paper :unimpressed:
Original post by Kamara7
Actually, the organic stuff might be my favourite part :tongue: Well... except when it comes to NMR questions in the exam :eek: Which bits do you find difficult?


Omg yes. The examples in my textbook are soft compared to that horror of a question on that paper :unimpressed:


If you do OCR A, all of Module 4.1 :/

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Original post by gooner_hsj
If you do OCR A, all of Module 4.1 :/

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Yeah, I do OCR A :smile: Omg that's my favourite module :lol: Is it remembering all the reagents and conditions? Quote/tag/PM me when you're stuck with something :h:
Original post by Kamara7
Yeah, I do OCR A :smile: Omg that's my favourite module :lol: Is it remembering all the reagents and conditions? Quote/tag/PM me when you're stuck with something :h:


I found isomers and free radical substitution fairly difficult

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Original post by gooner_hsj
I found isomers and free radical substitution fairly difficult

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I found that this video from Khan Academy really helped when I was doing free radical substitution: https://www.khanacademy.org/science/organic-chemistry/substitution-elimination-reactions/free-radical-reaction-alkanes/v/free-radical-reactions

Is it structural, optical or E/Z (cis/trans) you're stuck with?
Original post by Kamara7
I found that this video from Khan Academy really helped when I was doing free radical substitution: https://www.khanacademy.org/science/organic-chemistry/substitution-elimination-reactions/free-radical-reaction-alkanes/v/free-radical-reactions

Is it structural, optical or E/Z (cis/trans) you're stuck with?


Structural, stereo and E/Z. My teacher missed a few lessons and I wasn't really able to pick it up after. I asked him to go through it, but he was very brief and also, thank you for the video, I'm definitely going to have a look.

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Original post by gooner_hsj
Structural, stereo and E/Z. My teacher missed a few lessons and I wasn't really able to pick it up after. I asked him to go through it, but he was very brief and also, thank you for the video, I'm definitely going to have a look.

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OK, so isomers are molecules with the same chemical formula, have a different chemical structure. There are different types of isomers, including structural isomers and stereoisomers.

Structural isomers - these are molecules which have the same molecular formula but have a different structural/displayed formula. There are 3 types:
- Chain isomers: this is where the carbon skeleton can be arranged differently. So butane and methylpropane are chain isomers as they both have the same chemical formula (C4H10) but the difference between the two is that one of the CH3's in butane is taken out and placed on the middle carbon, so the carbon skeleton has been rearranged.
- Positional isomers: this is where a functional group has been placed on a different carbon atom. 1-chloropropane and 2-chloropropane are examples of this as the chlorine atom (the main functional group - halides) has been placed on a different carbon atom, but they have the same chemical formula.
- Functional group isomers: this is where the atoms in the molecules have been arranged to form a different functional group, but they still have the same chemical formula. So hex-1-ene and cyclohexane are examples of this as they both have the same chemical formula (C6H12) but the first one's an alkene and the second's an alkane (different functional groups).

Stereoisomers - there are E/Z (cis/trans) isomers and optical isomers (enantiomers), but I'll only go through E/Z :tongue:. Stereoisomers are molecules which have the same structural formula but have a different arrangement in space.

E/Z: C=C bonds have a lack of rotation around the double bonds. When the each of the carbons in the double bond have two different atoms or groups attached to them, you get an E and a Z isomer. You don't need to know about deciding priorities, but if the two higher priority groups are on the same side of the C=C double bond, then the molecule's the Z isomer, if they're on opposite sides, it's the E isomer, E for entgegen (opposite), Z for zusammen (together), knowing a tiny bit of German helped me with this :biggrin: This may not make sense until you look at diagrams or build models, it hard to put this into words. Maybe read this http://www.chemguide.co.uk/basicorg/isomerism/geometric.html#top until the red Note and then read this http://www.chemguide.co.uk/basicorg/isomerism/ez.html#top sorry, I can't explain E/Z properly using words, I'd need a whiteboard :biggrin:

Hope this helped! Others can correct this if need be :smile:
(edited 8 years ago)
Original post by Kamara7
OK, so isomers are molecules with the same chemical formula, have a different chemical structure. There are different types of isomers, including structural isomers and stereoisomers.

Structural isomers - these are molecules which have the same molecular formula but have a different structural/displayed formula. There are 3 types:
- Chain isomers: this is where the carbon skeleton can be arranged differently. So butane and methylpropane are chain isomers as they both have the same chemical formula (C4H10) but the difference between the two is that one of the CH3's in butane is taken out and placed on the middle carbon, so the carbon skeleton has been rearranged.
- Positional isomers: this is where a functional group has been placed on a different carbon atom. 1-chloropropane and 2-chloropropane are examples of this as the chlorine atom (the main functional group - halides) has been placed on a different carbon atom, but they have the same chemical formula.
- Functional group isomers: this is where the atoms in the molecules have been arranged to form a different functional group, but they still have the same chemical formula. So hex-1-ene and cyclohexane are examples of this as they both have the same chemical formula (C6H12) but the first one's an alkene and the second's an alkane (different functional groups).

Stereoisomers - there are E/Z (cis/trans) isomers and optical isomers (enantiomers), but I'll only go through E/Z :tongue:. Stereoisomers are molecules which have the same structural formula but have a different arrangement in space.

E/Z: C=C bonds have a lack of rotation around the double bonds. When the each of the carbons in the double bond have two different atoms or groups attached to them, you get an E and a Z isomer. You don't need to know about deciding priorities, but if the two higher priority groups are on the same side of the C=C double bond, then the molecule's the Z isomer, if they're on opposite sides, it's the E isomer, E for entgegen (opposite), Z for zusammen (together), knowing a tiny bit of German helped me with this :biggrin: This may not make sense until you look at diagrams or build models, it hard to put this into words. Maybe read this http://www.chemguide.co.uk/basicorg/isomerism/geometric.html#top until the red Note and then read this http://www.chemguide.co.uk/basicorg/isomerism/ez.html#top sorry, I can't explain E/Z properly using words, I'd need a whiteboard :biggrin:

Hope this helped! Others can correct this if need be :smile:


Thank you so much! This has been really helpful to me, I am in debt to you. Your explanations made it a lot clearer than what my teacher had said, I definitely feel more confident on the topic than what I did.

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Original post by gooner_hsj
Thank you so much! This has been really helpful to me, I am in debt to you. Your explanations made it a lot clearer than what my teacher had said, I definitely feel more confident on the topic than what I did.

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Phew, I'm glad it helped :smile:
Hey, does anyone have anything that illustrates Ph curves as I am struggling with them :frown:

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(edited 8 years ago)
Does anyone have june 2015 F324 and F325 papers with their markschemes please? Thanks
Original post by PlayerBB
Hey, does anyone have anything that illustrates Ph curves as I am struggling with them :frown:

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Hey check the last page of the F325 Notes, there's really only those pH curves that can be asked.
Original post by ForgottenApple
Thread is in progress. Comment if a link is broken and I'll fix it asap.

Hello I am ForgottenApple, I recently finish A Levels with some reasonable results (A*A*A* Maths, Physics & Chemistry). This thread is to help you achieve something similar at the same level. I created these resources for myself last year and have brought them up into a good enough order to help other people out. This thread is a chemistry counterpart to a new thread I've made this year for Chemistry and incorperates all but the practical element of the OCR Chemistry A Level course (to be revised in 2015) but nonetheless there is a full year of students who can benefit from these resources and any students who opt to resit thereafter.

Most notes I wrote last year, as well as the standard answers being made by me (idea from my college), definitions lists, legacy resources/past papers/bonus questions tend to be lifted :P

Link to physics thread
Unlike the physics thread
I'm going to sort of build this as I go so it may not be complete for a month-ish

Important Links
Physics and maths tutor: Includes extra past papers from other exam boards, and the extremely useful questions by topic
A Level Chemistry Website, mostly older spec past papers, and questions with solutions!
Memrise - Excellent for rote learning definitions, equations and reactions (Good iOS and Android App!)

F321
Definitions
Standard Answers

F322
Definitions
Standard Answers

F324
ah organic chemistry, I decided to go with a unique 'on a page' model for this unit, inspired by maths which condensed units down to a single page. I'm going to release a PDF version of this, so you can print out pages as required
Interactive Definitions
Interactive Important Reactions and Conditions
Full PDF of on a page
Standard answers compiled from all legacy and current specification
Legacy Past Papers



F325
Interactive Definitions
Notes
Standard Answers compiled from all legacy and current specification
Legacy Past Papers & This
Past Paper Spreadsheet Excel Template


Hi ForgottenApple, this looks great for my son (who is retaking AS and doing A2 in the summer). Does this ^^ contain all the links you've produced? Did you ever put your Past Paper Spreadsheet up? Thanks very much.
EDIT - the F321 link takes me to a OneDrive sign in page, is this correct?
(edited 8 years ago)
Don't bother getting the 2015 paper, you'll get it; just wait trust me.
Original post by Lemonpopsicle2
Hi ForgottenApple, this looks great for my son (who is retaking AS and doing A2 in the summer). Does this ^^ contain all the links you've produced? Did you ever put your Past Paper Spreadsheet up? Thanks very much.


I have not uploaded the spreadsheet, that includes all the links I've provided. There is another post on here that includes some extra resources, as well as some I've already provided so check them.
Original post by Lemonpopsicle2
Hi ForgottenApple, this looks great for my son (who is retaking AS and doing A2 in the summer). Does this ^^ contain all the links you've produced? Did you ever put your Past Paper Spreadsheet up? Thanks very much.
EDIT - the F321 link takes me to a OneDrive sign in page, is this correct?


Remade the link, try again :smile:
thank-you so much forgottenApple! You are very kind and generous to do this :wink:
good luck in the future whatever you do!
Are there any definitions for F321 mate?

Thanks for the Physics and Chem stuff anyways

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