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    http://s359.photobucket.com/albums/o...ent=Chem-2.png

    Is this an E or Z isomer
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    Z isomer
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    Z, I think

    E = Entergan = Together

    and Z = Zusaman = Apart.
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    I would say it's an E isomer as the carbon chains are opposite each other about the double bond.
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    it is an E/Trans isomer.
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    (Original post by RFextra)
    Z, I think

    E = Entergan = Together

    and Z = Zusaman = Apart.
    It's E. The Z means "together" and the E means "opposite"

    I always remembered it because Z is almost like an S, and same begins with an S

    (yes I am a little bit special )
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    (Original post by RFextra)
    Z, I think

    E = Entergan = Together

    and Z = Zusaman = Apart.
    Other way around dude:

    E - Entgegen - opposite

    Z - Zusammen - together
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    it's E-2-chloropent-3-ene
    a trans isomer (or E isomer)
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    My teacher always said this to me:

    Z - Ze same side (in a french accent :rolleyes:). The two CH3 groups aren't on the same side so I'd say E-isomer.
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    (Original post by RFextra)
    Z, I think

    E = Entergan = Together

    and Z = Zusaman = Apart.
    That's the wrong way round, zusammen means together
    And entgegen means opposite
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    (Original post by xXxBaby-BooxXx)
    It's E. The Z means "together" and the E means "opposite"

    I always remembered it because Z is almost like an S, and same begins with an S

    (yes I am a little bit special )
    Yh - my chemistry teacher remembers Z as "On zee zame zide" (like how a Dutch person would say "On the same side")
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    Remember it, as they're on Zee same side ^^;
    and if they are on the same side, they are cis-ters :P
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    Finally - some German came in use
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    (Original post by FadeOut101)
    it's E-2-chloropent-3-ene
    a trans isomer (or E isomer)
    Where did you get 5 carbons from? :p:

    It's Z-2-chlorobut-2-ene

    (Original post by Steven)
    My teacher always said this to me:

    Z - Ze same side (in a french accent :rolleyes:). The two CH3 groups aren't on the same side so I'd say E-isomer.
    That's not how E/Z assignments work, you need to look at the two heaviest atoms joined to the double bond first. So the two heaviest (first) atoms are chlorine and carbon which are on zee zame zide
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    (Original post by EierVonSatan)
    Where did you get 5 carbons from? :p:

    It's Z-2-chlorobut-2-ene



    That's not how E/Z assignments work, you need to look at the two heaviest atoms joined to the double bond first. So the two heaviest (first) atoms are chlorine and carbon which are on zee zame zide
    I was scrolling down this thread despairing at the lack of knowledge of the rules of Messrs Cahn, Ingold and Prelog. Your post saved what remains of my sanity. Eternal thanks.

    :tongue:
    • Thread Starter
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    ok, so the answer was E isomer

    However, if we rank the groups attached to the two central carbon atoms we get

    12__17
    __C=C
    1___12

    Therefore, the highest ranks are on the same side which SHOULD make them Z isomers BUT THEY ARE NOT

    Please xplain

    IGNORE the _
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    (Original post by jsmith6131)
    ok, so the answer was E isomer

    However, if we rank the groups attached to the two central carbon atoms we get

    12__17
    __C=C
    1___12

    Therefore, the highest ranks are on the same side which SHOULD make them Z isomers BUT THEY ARE NOT

    Please xplain

    IGNORE the _
    Listen to EVS, and not the others. If the mark scheme for said question says that the molecule you showed us is the E isomer, it is wrong and was written by idiots.
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    I emailed the exam board and they agreed that the mark scheme was WRONG
    Answer is Z isomer
 
 
 
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