AS Chemistry- helping each other out!
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Original post by ThatMadClown
look at whats around the carbocation
general pattern: if carbocation is at the end of chain its primary.
if theres two alkyl groups surrounding it s secondary.
if theres three alkyl groups surrounding then its tertiary.
general pattern: if carbocation is at the end of chain its primary.
if theres two alkyl groups surrounding it s secondary.
if theres three alkyl groups surrounding then its tertiary.
How is 2-methylhexan-1-ol a primary alcohol? It has 2 alkyl groups? Doesn't make sense!
Original post by rm_27
How is 2-methylhexan-1-ol a primary alcohol? It has 2 alkyl groups? Doesn't make sense!
Its primary cos the C attached to OH is attached to 2 H atoms
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Original post by 2-ethylbut-1-ene
What????? But that's not what you look at, it's the alkyl groups?
Original post by rm_27
What????? But that's not what you look at, it's the alkyl groups?
This way is easier
Basically, if the carbon attached to the OH is attached to 2 hydrogen atoms, it is primary
If the carbon attached to the OH is attached to 1 hydrogen atom, it is secondary
If the carbon attached to the OH is not attached to any hydrogens, it is tertiary
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Original post by rm_27
How is 2-methylhexan-1-ol a primary alcohol? It has 2 alkyl groups? Doesn't make sense!
are you talking about carbocations or alcohols? if alcohols you look at how many carbons surround the OH group
Original post by jontypickles
Is it an electrophilic addition reaction?
Hydrogenation is also called reduction.
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Just a thought that popped into my head, is there any way to distinguish between primary, secondary and tertiary alcohols if the molecule has more than one hydroxyl group in its structure?
Original post by jontypickles
Just a thought that popped into my head, is there any way to distinguish between primary, secondary and tertiary alcohols if the molecule has more than one hydroxyl group in its structure?
Best way would to oxidise them and then test to see what the products are using tollens to see if the product is an aldehyde or ketone.
Original post by ThatMadClown
Best way would to oxidise them and then test to see what the products are using tollens to see if the product is an aldehyde or ketone.
The product would be a mix of a ketone/ aldehyde so it would be hard to distinguish...
If the molecule has more than one hydroxyl group and it's in a different position (I.e. it's secondary in one place but primary in another) then you're probably stuck as that molecule isn't classified under one type of alcohol. You'd have to distinguish using other analytical techniques such as nmr.
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Original post by jontypickles
Okay well that is something i didn't know 
tell me more? Sorry for correcting you, was trying to help
tell me more? Sorry for correcting you, was trying to help I had a little bit of a look around and I found this - http://www.compoundchem.com/wp-content/uploads/2014/02/Organic-Reaction-Map-v4.pdf it seems to cover some stuff that we haven't gotten onto yet (like epoxides) but it could be useful.
I just made this this is a flowchart of all the reactions we need on my course. Let me know if there's is anything I've missed or got wrong, because there's bound to be
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this is a flowchart of all the reactions we need on my course. Let me know if there's is anything I've missed or got wrong, because there's bound to be Posted from TSR Mobile
Original post by jontypickles
I just made this this is a flowchart of all the reactions we need on my course. Let me know if there's is anything I've missed or got wrong, because there's bound to be
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this is a flowchart of all the reactions we need on my course. Let me know if there's is anything I've missed or got wrong, because there's bound to be Posted from TSR Mobile
Sweet! Might write up that sort of thing myself.
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?
Can someone explain how the bond polarity affects the reactivity?
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?
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
)
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.
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
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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