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    Can someone explain the nucleophillic substitution reaction with ammonia to me? Like I sort of understand the first bit. Ammonia has a lone pair so is a nucleophile. Then it does the normal stuff, the bit I don't get is with the second ammonia. Another thing is to do with bond enthalpy and bond polarity.
    Can someone explain how the bond polarity affects the reactivity?
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    (Original post by Super199)
    Can someone explain the nucleophillic substitution reaction with ammonia to me? Like I sort of understand the first bit. Ammonia has a lone pair so is a nucleophile. Then it does the normal stuff, the bit I don't get is with the second ammonia. Another thing is to do with bond enthalpy and bond polarity.
    Can someone explain how the bond polarity affects the reactivity?
    the nitrogen bonded to the amine (that was a haloalkane) has a positive charge.
    another nh3 donates its lonepair to the hydrogen bonded to the N on the amine and a bond forms, so you get an ammonium ion nh4+
    this leaves the N on the amine with a lone pair of electrons and the bonding electrons between H and N are taken by N when H forms a bond to the NH3 to make nh4+
    im not sure how clear that was but i would get a cgp revision textbook if ur doing aqa )
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    Can any one help with this question, it asks you to calculate the enthalpy change of the reaction. Also please could you show how you worked it out. Thanks


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    When is everyone doing task 3 for the Chen as AQA empa?


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    (Original post by Confusedbio)
    When is everyone doing task 3 for the Chen as AQA empa?Posted from TSR Mobile
    Is that the written paper? If it is we are doing it on the 8th of May.
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    (Original post by TeaAndTextbooks)
    Can any one help with this question, it asks you to calculate the enthalpy change of the reaction. Also please could you show how you worked it out. Thanks


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    soz this is probably late but don't you just do -(-1206.9)+(-635.1)= 571.8kjmol-1
    because using hess's law the enthalpy of the reaction is independent to the route taken so caco3 breaks down into its elements, and then goes to the product so u just add up the enthalpies but the arrow is the wrong way round for the first one so u do -(enthalpy of formation) and u add the second one
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    That's what I thought the answer was but the book said the answer was +178.3 I guess the book is wrong lol thanks for the help though I totally hate the energetics topic and born harber cycles good luck with your exams

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    (Original post by TeaAndTextbooks)
    That's what I thought the answer was but the book said the answer was +178.3 I guess the book is wrong lol thanks for the help though I totally hate the energetics topic and born harber cycles good luck with your exams

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    Yeah I can't see how it would be that?? Thanks and you too!

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    I do edexcel and I really need help.

    On the specification sometimes it says stuff like 6.3.b what does this mean???
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    (Original post by Rstlss)
    I do edexcel and I really need help.

    On the specification sometimes it says stuff like 6.3.b what does this mean???
    Its just like sub units but honestly just buy a cgp revision guide for your specification or use the edexcel endorsed textbook so you know you aren't missing out and details nd ull probably save time too!! You can also make spec notes from there if u want :yes:

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    (Original post by Azula)
    Its just like sub units but honestly just buy a cgp revision guide for your specification or use the edexcel endorsed textbook so you know you aren't missing out and details nd ull probably save time too!! You can also make spec notes from there if u want :yes:

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    I do that already , It's just like some bits aren't in the book however.
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    (Original post by Rstlss)
    I do that already , It's just like some bits aren't in the book however.
    Ohh I get you, I'm doing aqa chemistry

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    (Original post by Azula)
    Ohh I get you, I'm doing aqa chemistry Posted from TSR Mobile
    Has your school finished the course
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    Chem just really hurts my brain sometimes.
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    Lol Same. However, it is one of the hardest and most respected
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    (Original post by Super199)
    Has your school finished the course
    Na but we've only got like 2 topics left, what about you

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    (Original post by Azula)
    Na but we've only got like 2 topics left, what about you

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    We still have to do Resources.
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    guys do i have to study for the HSW in the chemistry AS edexcel textbook? please reply to me pleaaase
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    hi! Sorry if i've done this wrong this is my first post! I'm doing AQA AS Chem and the spec says "appreciate the usefulness of these reactions (nucleophillic substitution) in organic synthesis" but i don't really have any specific examples and was wondering if someone could help me out thank youuuu
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    Attention guys a TSR whatsapp study group has been set up.PM Sara_ara98.
 
 
 
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