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AQA AS Chemistry 7404/1 and 7404/2 - 27th May 2016 and 10th June 2016 watch

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    Hey can anyone show me their dehydrating ethanol and hydrating ethene mechanism? My teacher taught me differently than how it says in the textbook. I got taught to use sulphuric acid/phosphoric but the book said to use H+ ions?
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    Has anybody done the specimen paper from the first set? For the last question, why does the time taken increase to make the cross disappear with a larger conical flask?
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    For a larger conical flask, the concentration of the particles is less. Therefore, there are fewer collisons and the reaction is slower, which makes it takes longer for the reaction to be completed
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    (Original post by angellll)
    Has anybody done the specimen paper from the first set? For the last question, why does the time taken increase to make the cross disappear with a larger conical flask?

    Okay I'm gonna have difficulty wording this so hopefully it's clear enough?
    One of my teachers said that in a larger conical flask the solution would be 'thinner'/only a few mm high because its base is much wider, the solution would be more 'spread out' across the X compared to a smaller conical flask in which the solution would be a few cm high. So because of this, if the solution in the smaller conical flask was still a bit translucent, the cross would already be difficult to see, but for the same colour in the larger conical flask the cross would still be quite visible. This isn't much of a ~chemistry~ explanation though but it is what he said
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    (Original post by haes)
    Okay I'm gonna have difficulty wording this so hopefully it's clear enough?
    One of my teachers said that in a larger conical flask the solution would be 'thinner'/only a few mm high because its base is much wider, the solution would be more 'spread out' across the X compared to a smaller conical flask in which the solution would be a few cm high. So because of this, if the solution in the smaller conical flask was still a bit translucent, the cross would already be difficult to see, but for the same colour in the larger conical flask the cross would still be quite visible. This isn't much of a ~chemistry~ explanation though but it is what he said
    Thank you babe xx
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    (Original post by haes)
    Hey can anyone show me their dehydrating ethanol and hydrating ethene mechanism? My teacher taught me differently than how it says in the textbook. I got taught to use sulphuric acid/phosphoric but the book said to use H+ ions?
    Using H+ is just a shorthand way instead of writing thr whole acid, because all you really are interested in is the h+ from the acid.

    You can do any though, stick with what you are cimfortablw with
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    (Original post by haes)
    Hey can anyone show me their dehydrating ethanol and hydrating ethene mechanism? My teacher taught me differently than how it says in the textbook. I got taught to use sulphuric acid/phosphoric but the book said to use H+ ions?
    For Dehydrating Ethanol....Ive been told it is done this way...The H+ ions come from the acid...
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    Was anyone taught the mechanism like this?

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    (Original post by haes)
    Hey can anyone show me their dehydrating ethanol and hydrating ethene mechanism? My teacher taught me differently than how it says in the textbook. I got taught to use sulphuric acid/phosphoric but the book said to use H+ ions?
    For the hydrating ethene mechanism I've learnt it as this....The textbook also is the same... (You may have to zoom out it went weird)...
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    (Original post by haes)
    Was anyone taught the mechanism like this?

    Yeah, I was...But not in my AQA Chem text book??? Do we need to know it like this? It is the same...youre just showing the whole acid and not only the H+ from the acid.
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    (Original post by haes)
    Was anyone taught the mechanism like this?

    yeh I was taught it like this
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    (Original post by AdamWallisjr)
    Yeah, I was...But not in my AQA Chem text book??? Do we need to know it like this?
    Yes which is why i'm slightly worried. Do you think they'll accept both methods?
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    (Original post by haes)
    Yes which is why i'm slightly worried. Do you think they'll accept both methods?
    Im gonna be safe and use the one with the whole acid in...If its right they cant take the mark away for too much detail right?
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    (Original post by haes)
    Yes which is why i'm slightly worried. Do you think they'll accept both methods?
    I've been taught that too, which textbook do you use?

    i think it should be acceptable
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    (Original post by haes)
    Hey can anyone show me their dehydrating ethanol and hydrating ethene mechanism? My teacher taught me differently than how it says in the textbook. I got taught to use sulphuric acid/phosphoric but the book said to use H+ ions?
    That is right the H+ ions are present in the acid.
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    If you do nucleophilic substitution with CN to something like 3-bromopentane and have to name the compound formed, does the carbon bonded to the nitrogen become carbon number 1 and therefore have the name as 2-ethylbutanenitrile
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    (Original post by haes)
    Yes which is why i'm slightly worried. Do you think they'll accept both methods?
    yes i think so because if you look in the eletrophilic addition where sulfuric acid is being added to an alkene its the backwards version of this and they also show the mechanism for alkene to alcohol with H+ so i think bout would be accepted
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    (Original post by haes)
    Yes which is why i'm slightly worried. Do you think they'll accept both methods?
    Well the only part of it that is relevant really is the H+, I was taught it that way and I'm pretty sure it will be fine. Good luck everyone.
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    Ive got a good idea, If we all only show the H+ ions then they will have to accept it.
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    (Original post by sameer99)
    I've been taught that too, which textbook do you use?

    i think it should be acceptable
    CGP
 
 
 
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