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    I'm doing edexcel A2 Chemistry and we've got homework on isomerism and I'm really stuck. Some of the types of isomerism I can't even find in the textbook.

    I've done one question but I'm not sure if its right.
    It says to draw two alcohol molcules with the formula C4H10O that show positional isomerism, and I've done (obviously i've drawn them)

    CH3CH2CH2CH2OH - butanol? Or do I need to put butan-1-ol?
    CH3CH2CHOHCH3 - butan-2-ol

    I'm not 100% sure what positional isomerism is, as its not mentioned in my book (nor is functional group isomerism). Tried looking it up but it wasn't very clear.

    Second question:
    Show the structures of two molecules of formula C4H10O which are stereoisomers.

    Then you have to state what type of isomerism it is. I'm thinking I need to draw optical isomers because it goes on to say about explaining how to distinguish between the two stereoisomers - cant be that as there needs to be four groups. So I have no clue Okay, maybe it can?. It also says "name the feature of the molecules which allows this type of isomerism"


    Third question:

    Show the structures of two molecules of formula C4H10O which show the type of isomerism called functional group isomerism.

    Please help. I've got a massive pile of homework and I'm stuck on pretty much all of them! :confused:
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    (Original post by LadyLoveDisdain)
    CH3CH2CH2CH2OH - butanol? Or do I need to put butan-1-ol?
    CH3CH2CHOHCH3 - butan-2-ol
    Yep, you need the butan-1-ol. Looks good

    I'm not 100% sure what positional isomerism is, as its not mentioned in my book (nor is functional group isomerism). Tried looking it up but it wasn't very clear.
    It's just altering the position of a functional group on a chain.

    Second question:
    Show the structures of two molecules of formula C4H10O which are stereoisomers.

    Then you have to state what type of isomerism it is. I'm thinking I need to draw optical isomers because it goes on to say about explaining how to distinguish between the two stereoisomers - cant be that as there needs to be four groups. So I have no clue Okay, maybe it can?. It also says "name the feature of the molecules which allows this type of isomerism"
    It is optical isomerism :yes:


    Third question:

    Show the structures of two molecules of formula C4H10O which show the type of isomerism called functional group isomerism.
    Functional group isomerism is when you alter one type of functional group into another so (for example) an alcohol into an ether.
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    Thank you!

    I'm stuck...on another question :rolleyes:
    "Dehydration of 2-hydroxybutanoic acid forms two stereoisomers. Give the structures of these two isomers and name the type of stereoisomerism which is show".

    Does that form an acid anhydride? What would it be, just butanoic anhydride? I'm not sure what to do with the hydroxy.

    I'm thinking maybe its going to be E-Z isomerism, but I have no idea how to draw them :confused:
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    2-hydroxybutanoic acid: CH3CH2CH(OH)COOH

    Dehyrdration (loss of water) leaves: CH3CH=CHCOOH

    And this compund has geometric isomerism...that help?
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    (Original post by EierVonSatan)
    2-hydroxybutanoic acid: CH3CH2CH(OH)COOH

    Dehyrdration (loss of water) leaves: CH3CH=CHCOOH

    And this compund has geometric isomerism...that help?
    Thanks for your help! Just found it in a different text book and was about to ask whether it was correct. Thanks so much!
 
 
 
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