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GCSE OCR 21st Century B7 C7 P7 - W/C - Monday 20th June 2016 Watch

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    (Original post by Speedbird129)
    PM me your email address and I will try and send some P7 resources to you. I dont own them btw!.
    And I can't upload them to the thread because it says they are too big.
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    Does anyone have any tips for remembering information (e.g functional group, properties, reactivity etc) about alkanes, alkenes, carboxylic acids and esters? It would be greatly appreciated, seen as I'm worried I'll get mixed up in the exam
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    (Original post by g3ob)
    Does anyone have any tips for remembering information (e.g functional group, properties, reactivity etc) about alkanes, alkenes, carboxylic acids and esters? It would be greatly appreciated, seen as I'm worried I'll get mixed up in the exam
    Our teacher taught us a mnemonic for remembering how many carbon atoms are in the chemicals. It goes like this, Monkeys Eat Peanut Butter. M - one carbon atom E - two carbon atoms P - three carbon atoms B - four carbon atoms

    For example Methane comes under monkey and contains only one carbon atom. Whereas Butane contains 4 carbon atoms. For alkanes, these are surrounded by hydrogen atoms and so once you know how many carbon atoms are in them, the rest is simple! This also applies to alcohols and carboxylic acids.
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    This is a youtube video of "Cowen Physics" doing a walkthrough of the 2014 P7 paper. Feel free to check it out!

    https://www.youtube.com/watch?v=ctoSPFWc5rU
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    (Original post by Speedbird129)
    Our teacher taught us a mnemonic for remembering how many carbon atoms are in the chemicals. It goes like this, Monkeys Eat Peanut Butter. M - one carbon atom E - two carbon atoms P - three carbon atoms B - four carbon atoms

    For example Methane comes under monkey and contains only one carbon atom. Whereas Butane contains 4 carbon atoms. For alkanes, these are surrounded by hydrogen atoms and so once you know how many carbon atoms are in them, the rest is simple! This also applies to alcohols and carboxylic acids.
    Thanks!
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    (Original post by g3ob)
    Thanks!
    Thanks for the follow btw
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    Hey guys! im in this absolute g's class too. i like p7 interesting topic, just wish there were more past papers we can try on.
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    (Original post by rapidshock)
    Hey guys! im in this absolute g's class too. i like p7 interesting topic, just wish there were more past papers we can try on.
    Who's the G ? Mr. Cowen ?


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    (Original post by MR.ANONYMOUS 786)
    Who's the G ? Mr. Cowen ?


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    oh i mean im the op's class and school. i dont know who mr. cowen is - but our science teacher is pretty alright too!
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    (Original post by rapidshock)
    oh i mean im the op's class and school. i dont know who mr. cowen is - but our science teacher is pretty alright too!
    Lol. Mr Cowen is an OG.


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    c7 is the worst!!!
    have you all revised additional content
    im yet to start and have triple
    any advice/tips on effective ways to memorise
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    Got 100UMS on C7 AMA
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    (Original post by richpanda)
    Got 100UMS on C7 AMA
    Do you have any advice on this exam and do you have any ways to remember how to draw esters as I struggle with this. Thanks
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    (Original post by Speedbird129)
    Do you have any advice on this exam and do you have any ways to remember how to draw esters as I struggle with this. Thanks
    My method for naming/drawing esters:

    In the name, you put the alcohol first and the carboxylic acid second. A comes before C in the alphabet, so this makes sense.

    For the drawing, it's the inverse. You want to start with drawing the carboxylic acid part first (on the left hand side), then the alcohol.

    I'll give you a worked example. The question says draw the ester formed when butanoic acid is heated with ethanol (with an acid catalyst ). Firstly, name the ester (ethyl butanoate). Then start by drawing 4 carbons, draw the relevant hydrogens on the first 3 carbons, then the double bond with oxygen and the single bond with oxygen. Then attach to the other end of the oxygen that is single bonded the first carbon from the ethanol, and then the second carbon afterwards.

    Remember also that water is formed in this reaction as you lose a H+ from the carboxylic acid, and an OH- from the alcohol, which react together to form H2O.
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    (Original post by richpanda)
    My method for naming/drawing esters:

    In the name, you put the alcohol first and the carboxylic acid second. A comes before C in the alphabet, so this makes sense.

    For the drawing, it's the inverse. You want to start with drawing the carboxylic acid part first (on the left hand side), then the alcohol.

    I'll give you a worked example. The question says draw the ester formed when butanoic acid is heated with ethanol (with an acid catalyst ). Firstly, name the ester (ethyl butanoate). Then start by drawing 4 carbons, draw the relevant hydrogens on the first 3 carbons, then the double bond with oxygen and the single bond with oxygen. Then attach to the other end of the oxygen that is single bonded the first carbon from the ethanol, and then the second carbon afterwards.

    Remember also that water is formed in this reaction as you lose a H+ from the carboxylic acid, and an OH- from the alcohol, which react together to form H2O.
    Thanks, this is really helpful. Please may you also do stuff to do with titrations as this seems complicated?
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    (Original post by Speedbird129)
    Thanks, this is really helpful. Please may you also do stuff to do with titrations as this seems complicated?
    okay do you do moles in C7 or C6? I can't remember.
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    (Original post by richpanda)
    okay do you do moles in C7 or C6? I can't remember.
    I don't remember doing them at all?
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    (Original post by richpanda)
    My method for naming/drawing esters:

    In the name, you put the alcohol first and the carboxylic acid second. A comes before C in the alphabet, so this makes sense.

    For the drawing, it's the inverse. You want to start with drawing the carboxylic acid part first (on the left hand side), then the alcohol.

    I'll give you a worked example. The question says draw the ester formed when butanoic acid is heated with ethanol (with an acid catalyst ). Firstly, name the ester (ethyl butanoate). Then start by drawing 4 carbons, draw the relevant hydrogens on the first 3 carbons, then the double bond with oxygen and the single bond with oxygen. Then attach to the other end of the oxygen that is single bonded the first carbon from the ethanol, and then the second carbon afterwards.

    Remember also that water is formed in this reaction as you lose a H+ from the carboxylic acid, and an OH- from the alcohol, which react together to form H2O.
    I've looked up on a couple of websites and they all say that the carboxylic acid loses the OH and the alcohol loses the H to make H20??
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    (Original post by Speedbird129)
    I don't remember doing them at all?
    Okay so what is it that you struggle with for titrations? I can remember finding the equations difficult because I didn't understand the units, or what was going on.

    Don't worry about the moles bit.
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    (Original post by Speedbird129)
    I've looked up on a couple of websites and they all say that the carboxylic acid loses the OH and the alcohol loses the H to make H20??
    Perhaps- but a carboxylic acid is an acid so it will often lose a H+. However this stuff doesn't matter- both the carboxylic acid and alcohol have a OH group, so whichever loses which the product will still be the same.
 
 
 
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