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OCR A 2016 Chemistry A* A-Level Resources

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Just posted this on my grow your grades thread not sure if it will be helpful fr anyone.
I have made a list of questions from the specification of OCR A (Old Specification) for the A2 unit 1 Module 1 and Unit 2 Module 3 :Transition metals. They are just the questions at the moment have not gotten round to typing up the answers yet but have made them. Might be helpful to see which questions you have no idea on how to answer and an alternative to doing the past papers over and over. Hope its helpful! (I'm doing A2 course at the moment got an A at AS and really want an A this year)

A2 Chemistry Unit 1 Module 1 questions.docx15.7KB

A2 Chemistry Unit 2 Module 3 Questions.docx17.6KB

Reply 101

ForgottenApple

Original post by CSLady

I don't like that marks aren't shown. You are passing an exam at the end of the day and judging difficulty from the marks is a key skill.

Reply 102

CSLady

Original post by ForgottenApple

I don't like that marks aren't shown. You are passing an exam at the end of the day and judging difficulty from the marks is a key skill.

They are not real exam questions they are made up. They are questions I made up from the specification. So I took the specification and reworded it into questions. looking back I didn't make that clear in this post while I did in the one on my grow your grade thread. There are no marks cause I don't know how many marks they would be as they are not real exam questions. They are just a guideline and cover all areas on the specification in those particular module. Sorry for any confusion.

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(edited 8 years ago)

Reply 103

thad33

Original post by ForgottenApple

Always understand the steps you're taking or you're wasting your time. Do the papers from Jan 10 onwards from other boards, this is when the A* questions started popping up and exam boards steal from each other.

The reason I say to practice the other boards aswell is because it develops a real deep rooted understanding which is what's needed.

So past papers from other boards are important also yes?

I'm taking a year out and redoing F325 because I flopped on the day. I done pretty well on F324 and coursework getting a high A and A* respectively but felt I should have got higher considering how well I knew the spec and the past papers that I done, however that exam was brutal.

I don't find the learning difficult or even answering questions but there were a few questions that, in an exam environment, threw me off the pace and I panicked.

I'm going for an A*, as close to 100% as possible, in F325. What do you propose I should do beyond going through the textbook and OCR past papers in order to achieve it?

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Reply 104

Xetter

Hello,

I was skimming through exam pro and came across this question. For 'Reaction 3' it asks for the reagent, which according to the markscheme is Na2CO3.

Is this somthing we need to know or might this be from the AQQ spec?

Cheers

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1456834867382.jpg48.1KB

Reply 105

Danllo

Mg(NO3)2 how would I assign the oxidation numbers to this ?

Reply 106

PlayerBB

Original post by Danllo

Mg(NO3)2 how would I assign the oxidation numbers to this ?

Mg is always 2+ and Oxygen in this case is 2- (go over the oxidation number rules), the overall charge of the compound is zero, so do a normal algebra equation of 2+2x+6(-2)=zero and you should get x=5+ which is the oxidation number for Nitrogen

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(edited 8 years ago)

Reply 107

ForgottenApple

Original post by Xetter

The only ones you need to know are the ones in the OCR specification.

Reply 108

SklIsMentalAbuse

Hey guys. If you can help me how you work this question out I'd be really grateful.

Hydrogen peroxide reacts in a first order reaction with a half life of 27 secs. If the intitiam concentration is 1.60 mol dm-3, what is the conc after 81 secs.

Reply 109

Danllo

I was searching on Google for stretch and challenge questions for A2. I found this document (link below)

http://www.cotham.bristol.sch.uk/_files/science/ocr_a2_chemistry_teacher_guide.pdf

But this document only contains answers. Does anyone know where I could find the questions to these answers ?

Reply 110

Professor L

Original post by SklIsMentalAbuse

Its half life is 27 seconds, meaning that every 27 seconds, its concentration will decrease by half. 81 seconds equates to 3 half lives (27 x 3), so the concentration will decrease by half 3 times. So to get from its starting [ ] to its [ ] after 81 secs, you do 1.60 x 1/2 x 1/2 x 1/2.

Don't hesitate to ask me more questions, I'll try to answer them :smile:

(edited 8 years ago)

Reply 111

ForgottenApple

Extract from my past paper spreadsheet

Reply 112

ForgottenApple

Original post by Kamara7

Its half life is 27 seconds, meaning that every 27 seconds, its concentration will decrease by half. 81 seconds equates to 3 half lives (27 x 3), so the concentration will decrease by half 3 times. So to get from its starting [ ] to its [ ] after 81 secs, you do 81 x 1/2 x 1/2 x 1/2.

Don't hesitate to ask me more questions, I'll try to answer them :smile:

Good answer. A simple way to represent this, providing you do maths, is [A](1/2)ⁿ where n is the number of half lives and [A] is the initial concentration of the whatever is reacting. This will work with any numbers they give though this is beyond the scope of the course but understanding it is a good and quick checking mechanism. Simple way is Kamara. Either is good.

(edited 8 years ago)

Reply 113

Professor L

Original post by ForgottenApple

Extract from my past paper spreadsheet

Omg, you've done so well in every one of your retest papers, well done! :biggrin:

I'm just praying for this year's C4 exam to be nicer than the 2015 one :bawling:

Reply 114

dpoojaraa

Original post by Kamara7

Its half life is 27 seconds, meaning that every 27 seconds, its concentration will decrease by half. 81 seconds equates to 3 half lives (27 x 3), so the concentration will decrease by half 3 times. So to get from its starting [ ] to its [ ] after 81 secs, you do 81 x 1/2 x 1/2 x 1/2.

Don't hesitate to ask me more questions, I'll try to answer them :smile:

Please can you explain why you have used 81secs? Instead of 1.6 mol dm-3?

Reply 115

Professor L

Original post by dpoojaraa

Please can you explain why you have used 81secs? Instead of 1.6 mol dm-3?

Oh God, I made a mistake, you're right :smile:

I'll edit it.

I'm gonna let @SklIsMentalAbuse know just in case.

(edited 8 years ago)

Reply 116

ForgottenApple

Original post by Kamara7

Oh God, I made a mistake, you're right :smile:

I'll edit it.

I'm gonna let @SklIsMentalAbuse know just in case.

Didn't even notice, good spot!

Reply 117

LThomas694

I'm gonna start doing past papers asap because I need to get an A to get into uni! Is it worth doing edexcel, AQA or legacy past papers now so I don't run out of OCR past papers too long before the exam or should I just do OCR ones?
Also how is everyone prepping for the identification of organic compounds evaluative task? The description is so vague so I'm not really sure what I should be focusing on.
Thanks :smile:

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Reply 118

Xetter

The identification of organic compounds task is easy. Go over things like colour changes and whether or not things fizz etc.

Also make sure you're happy drawing organic molecules.

Don't worry too much about it, everyone in my class scored high! :smile:

Reply 119

thad33

Original post by LThomas694

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There aren't too many OCR past papers so I'm going to do them all once I finish the theory and then go through AQA and Edexcel past papers after. Then I'll redo OCR past papers again the week leading up to the exams.