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    dw
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    no CL > H surely? the CH3 counts towards the butene chain
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    (Original post by Acruzen)
    no CL > H surely? the CH3 counts towards the butene chain
    Yeah so why would it be C?
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    (Original post by Lunch_Box)
    Yeah so why would it be C?
    E - Two elements that aren't in the chain are opposite.
    2 - Chlorine is on the second carbon atom.
    But - 4 Carbons in the chain.
    2 - The double bond is on the second carbon.
    ene- There is a double bond, so the suffix is that of an alkene.
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    (Original post by Lunch_Box)
    Yeah so why would it be C?
    what one do you expect it to be?
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    There isn't another Cl group on the other side is there? So surely Cl doesn't take precedence here. I got C as the answer.
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    (Original post by Lunch_Box)


    I was led to assume that the main priority groups were the ones with the greater mass. So then why is the answer C, if Cl > CH3?
    I believe the correct answer is D. The two highest priority groups are the chlorine and methyl. They are on the same side of the double bond, hence Z.
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    It's C. The 2 isomers there can be are having the methyl groups on the same side of the double bond, but on different Carbons, or on opposite sides of the double bond (on different Carbons). They are on opposite sides, which makes it E - E stands for Entganger, or opposite. The Carbon chain is made up of 4 Carbons with a double bond, so it is Butene. The molecule can be viewed from any direction, so the number which corresponds to which Carbon the Chlorine is on will always be the smallest one when counting from either end, which in this case means the 2nd Carbon (from the right hand side). This makes the answer C.

    Hope that's clear!
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    (Original post by charco)
    I believe the correct answer is D. The two highest priority groups are the chlorine and methyl. They are on the same side of the double bond, hence Z.
    Charco is correct. The naming system only takes into account the mass of the group (only the C for a CH3, only the O for OH etc)

    It has nothing to do with what is in the chain or not. Although this is of-course chemically relevant.

    For a through description look up the Cahn-Ingold-Prelog rules. These are the internationally recognised rules used to label E/Z and optical isomers and are the ones you will have learn't about.
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    Don't understand why the right answer is being negged-chlorine has a higher atomic mass than carbon, carbon has a higher one than hydrogen, hence (Z).

    http://www.chemspider.com/Chemical-S...e.4575767.html
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    http://chemicalguy.files.wordpress.c...if?w=535&h=191

    found this, not sure if it helps
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    (Original post by Midlander)
    Don't understand why the right answer is being negged-chlorine has a higher atomic mass than carbon, carbon has a higher one than hydrogen, hence (Z).

    http://www.chemspider.com/Chemical-S...e.4575767.html
    Yeah, why is my post neg rated? (not saying it was you Midlander)
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    Don't know JM-I tried repping you for it but alas I'm out for today. Your answer is right.
 
 
 
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