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OCR AS - Chemistry Unit F322 - Chains, energy and resource - REVISION! watch

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    So, I was thinking it'd be a good idea for people sitting this exam (or a similar one if it's applicable) to ask/answer questions.

    Here's how it works:

    I will ask a question, someone will hopefully answer it and then ask another question! Then anyone can join in and it'll hopefully be useful for everyone

    Here goes:

    Define the term electrophile.
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    Tip for you guys that are taking this exam... you have to do as many application questions as possible. Trust me, the past papers of the old spec does not gear you up for the real exam.
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    (Original post by J DOT A)
    Tip for you guys that are taking this exam... you have to do as many application questions as possible. Trust me, the past papers of the old spec does not gear you up for the real exam.
    Yeah I know :eek: my teacher gave our class an old "How Far, How Fast?" paper and then a recent one and we were all like :ahhhhh:
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    (Original post by Joseppea)
    Yeah I know :eek: my teacher gave our class an old "How Far, How Fast?" paper and then a recent one and we were all like :ahhhhh:
    Yeah exactly the mistake I made, thus I am retaking this unit again!
    Just make sure your organic chemistry is good and your sorted. I have done A2 so this should be alot easier I am hoping
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    Is there a thread of this kind going on for A2? :erm:
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    (Original post by Joseppea)
    Here goes:

    Define the term electrophile.
    Crap book is crap.

    erm.. a positively charged species that is attracted to a negatively charged species. Or something like that. I'd probably write delta-positive/delta-negative in the exam.

    Define the term isomer.
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    (Original post by Contrad!ction.)
    Crap book is crap.

    erm.. a positively charged species that is attracted to a negatively charged species. Or something like that. I'd probably write delta-positive/delta-negative in the exam.

    Define the term isomer.
    What do you mean by the book is crap...I feel the book has good information related to the course!
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    (Original post by patra)
    What do you mean by the book is crap...I feel the book has good information related to the course!
    Just don't rely on it. One of my Chemistry teachers avoids it like the plague whilst the other practically forces it upon us. Just so happens that the one who avoids it is pretty much the best teacher in the school - definitely one of them, anyway. It gives quite a lot of irrelevant stuff and I reckon it could be more succinct.

    Saying that, considering I'm self teaching 3 further maths modules from the official OCR books, anything I don't understand gets pinned on how crap the book is so ...head of maths says the books are crap to make sure he keeps his job
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    (Original post by Contrad!ction.)
    Just don't rely on it. One of my Chemistry teachers avoids it like the plague whilst the other practically forces it upon us. Just so happens that the one who avoids it is pretty much the best teacher in the school - definitely one of them, anyway. It gives quite a lot of irrelevant stuff and I reckon it could be more succinct.

    Saying that, considering I'm self teaching 3 further maths modules from the official OCR books, anything I don't understand gets pinned on how crap the book is so ...head of maths says the books are crap to make sure he keeps his job
    By the book is best.

    On the last exam, there were question you couldn't possibly know the answer to if you hadn't gone over the book.

    What did everyone get in unit 1?

    Also, I've a question.

    Draw 2 repeat units of Poly(propene), from the polymerisation of
    H3C---CH===CH2

    Does it matter if you start your repeat units on the Carbon that has the methyl group, or is it the otherway round?
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    (Original post by patra)
    What do you mean by the book is crap...I feel the book has good information related to the course!
    The book is the course
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    (Original post by SteveCrain)
    By the book is best.

    On the last exam, there were question you couldn't possibly know the answer to if you hadn't gone over the book.
    Well, I didn't use the book. What question was this?

    (Original post by SteveCrain)
    Also, I've a question.

    Draw 2 repeat units of Poly(propene), from the polymerisation of
    H3C---CH===CH2


    Does it matter if you start your repeat units on the Carbon that has the methyl group, or is it the otherway round?
    I've been working through the same paper as you, it seems

    I did it as
    .......H3C.....H.....H3C......H
    ------C-------C------C------C----
    .......H.........H........H..... ..H

    lol, crudeness... It shouldn't matter though, it's the same principle as drawing, say, 2-chloropentane - you could go from either end, have it 2 or 4 along.

    It looks neater than my drawing though
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    haha, here we go third time lucky

    (Original post by Contrad!ction.)
    Define the term isomer.
    I believe the answer is 'a molecule with the same number of atoms but a different arrangement of atoms in space'

    But it depends on whether or not its structural or stereo isomerism

    ok next question

    what are primary, secondary and tertiary alcohols oxidised to? (state reactants and conditions)
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    (Original post by Contrad!ction.)
    Well, I didn't use the book. What question was this?



    I've been working through the same paper as you, it seems

    I did it as
    .......H3C.....H.....H3C......H
    ------C-------C------C------C----
    .......H.........H........H..... ..H

    lol, crudeness... It shouldn't matter though, it's the same principle as drawing, say, 2-chloropentane - you could go from either end, have it 2 or 4 along.

    It looks neater than my drawing though
    Yeh I did that; MS suggests otherwise, though. Probably doesn't matter.

    And I can't remember the exact questions, there was one about uses of ammonia, and aside from that hte book explained everything other question on the exam.
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    (Original post by SteveCrain)
    Yeh I did that; MS suggests otherwise, though. Probably doesn't matter.

    And I can't remember the exact questions, there was one about uses of ammonia, and aside from that hte book explained everything other question on the exam.
    For some reason, our head of Chem (who won't let me resit F321, grr) has only given us the papers, but not the mark scheme. >.<

    I managed to answer everything but screwed myself over with that big cyclohexane question because I didn't take the q in properly and answered it all with silver nitrate stuff. I made some stupid mistakes in there as well, like forgetting that molecule shape.

    (Original post by viksta1000)
    what are primary, secondary and tertiary alcohols oxidised to? (state reactants and conditions)
    Tertiary isn't. Primary alcohols are oxidised to aldehydes by distillation or carboxylic acids by reflux. Secondary alcohols are oxidised to ketones.

    Describe briefly how fractional distillation can be used to convert crude oil into a small number of fractions [4]
    Stolen from my teacher
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    (Original post by viksta1000)
    what are primary, secondary and tertiary alcohols oxidised to? (state reactants and conditions)
    (Original post by Contrad!ction.)
    Tertiary isn't. Primary alcohols are oxidised to aldehydes by distillation or carboxylic acids by reflux. Secondary alcohols are oxidised to ketones.
    oooh 2 / 3 mate lol
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    (Original post by viksta1000)
    oooh 2 / 3 mate
    I've added a question now

    I know, I need to brush up on my conditions of reaction. Going through past papers, that's where I'm losing my marks.

    I love how we're ignoring enthalpy/rates. Because they suck.
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    (Original post by Contrad!ction.)
    I've added a question now

    I know, I need to brush up on my conditions of reaction. Going through past papers, that's where I'm losing my marks.

    I love how we're ignoring enthalpy/rates. Because they suck.
    Oi, don't go changing the subject, I expect you to get full marks on my question and nothing less before we progress onto another question lol....and yes they do suck

    (Original post by Contrad!ction.)
    Describe briefly how fractional distillation can be used to convert crude oil into a small number of fractions [4]
    Stolen from my teacher
    difference sized fractions = different intermolecular bond strengths = different amount of energy needed to break bonds = different boiling points = different condensing points - so each fraction condenses at a difference point and hence seperation

    I believe I've covered all the basics for full marks on that question, thank you very much


    Describe two ways to make ethanol (state reactants and conditions)
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    (Original post by viksta1000)
    Oi, don't go changing the subject, I expect you to get full marks on my question and nothing less before we progress onto another question lol....and yes they do suck
    No idea

    (Original post by viksta1000)
    difference sized fractions = different intermolecular bond strengths = different amount of energy needed to break bonds = different boiling points = different condensing points - so each fraction condenses at a difference point and hence seperation

    I believe I've covered all the basics for full marks on that question, thank you very much
    Didn't mention heating the crude oil

    (Original post by viksta1000)
    Describe two ways to make ethanol (state reactants and conditions)
    Obsessed with alcohol are we?

    bleh, as soon as you talk about mechanisms, I'm screwed. I can do electrophilics and polymerisation and to a certain degree free radical, but other than that, I'm crap.
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    (Original post by Contrad!ction.)
    No idea
    reactants - potassium/sodium dischromate
    conditions - H2SO4 catalyst

    (Original post by Contrad!ction.)
    Didn't mention heating the crude oil
    I think you'll find I mentioned boiling points which counts as heating

    (Original post by Contrad!ction.)
    Obsessed with alcohol are we?
    Yes, its the only thing that's going to get me through this revision stress

    (Original post by Contrad!ction.)
    bleh, as soon as you talk about mechanisms, I'm screwed. I can do electrophilics and polymerisation and to a certain degree free radical, but other than that, I'm crap.
    Cut the crap and answer the question lol

    what are you getting stuck on maybe I can help?
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    (Original post by viksta1000)
    reactants - potassium/sodium dischromate
    conditions - H2SO4 catalyst
    ah poo, I actually know them. In exams, I reckon I'm going to just slap 'SULPHURIC ACID!!!!!' everywhere

    (Original post by viksta1000)
    I think you'll find I mentioned boiling points which counts as heating
    psh, the exam board disagrees

    (Original post by viksta1000)
    Yes, its the only thing that's going to get me through this revision stress
    I've already got mine here

    (Original post by viksta1000)
    Cut the crap and answer the question lol
    fermentation using an enzyme I've forgotten the name of, or some sort of catalysed reaction I've forgotten about

    XYMASE! AND STEAM! ADDED TO ETHENE! BY ELECTROPHILIC ADDITION!
    (Original post by viksta1000)
    what are you getting stuck on maybe I can help?
    Chemistry?
 
 
 
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