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    I cannot do these :confused: help please can i have some hints especially for question 2 as the end of the chain has ch(Ch3)2 do i put c-h on top then ch3- ch3 on the rhs and the bottom??
    ch3ch3ch(ch3)ch3
    ch3ch(ch3)ch(ch3)2
    ch3ch2ch(ch3)ch2ch3
    (c2h5)2chch(ch3)ch(Ch3)2
    ch3ch2c(ch3)2ch(ch3)2
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    (Original post by ghostkillah)
    I cannot do these :confused: help please can i have some hints especially for question 2 as the end of the chain has ch(Ch3)2 do i put c-h on top then ch3- ch3 on the rhs and the bottom??
    ch3ch3ch(ch3)ch3
    ch3ch(ch3)ch(ch3)2
    ch3ch2ch(ch3)ch2ch3
    (c2h5)2chch(ch3)ch(Ch3)2
    ch3ch2c(ch3)2ch(ch3)2
    CH3CH(CH3)CH3 is simply a central carbon with three CH3 groups and 1 H group, that is a t-butyl - H(ie butane).

    you are thinking of drawing out a 3D structural formula, remember they are tetrahedral, so it shouldn't matter which way you put them, just as long as the question doesn't ask you for optical isomers, or something along those lines. On paper which is 2D, it'd be fine to draw the H either on top, bottom, left or right, it doesn't matter.
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    thanks for q1 right i think have got the hang of it
    can u check these...
    1. 2-methylbutane
    2. 1,1,2 - trimethylbutane
    3. 3 - methylpentane
    4. No idea need help
    5. 1,1,2,2 - tetramethylpentane
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    (Original post by ghostkillah)
    thanks for q1 right i think have got the hang of it
    can u check these...
    1. 2-methylbutane
    2. 1,1,2 - trimethylbutane
    3. 3 - methylpentane
    4. No idea need help
    5. 1,1,2,2 - tetramethylpentane
    might just be wise for some one to confirm these, I have never really liked naming these stuff, though I'd prefer drawing them from names rather than naming them(which I see as pain up the a***):woo:

    though I can confirm 1 is correct!
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    Provisional answers:

    2-methylbutane
    2,3-dimethylbutane
    3-methylpentane
    3-ethyl-4,5-dimethylhexane
    2,3,3-trimethylpentane

    Now going to get pen and paper as visualizing proved harder than expected!!!!!
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    Having written them out, i can see 4) should be: 4-ethyl-2,3-dimethylhexane. It is ethyl before methyl right shengoc?
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    (Original post by ghostkillah)
    thanks for q1 right i think have got the hang of it
    can u check these...
    1. 2-methylbutane
    2. 1,1,2 - trimethylbutane
    3. 3 - methylpentane
    4. No idea need help
    5. 1,1,2,2 - tetramethylpentane
    Doing them in your head is quite hard, so it's worth getting a pen and paper. Brackets represent a group coming off the previous carbon. Remember carbons will always have 4 bonds.

    First identify the longest carbon chain and write it down. Then look at the carbon groups you havnt included, methyl=CH3, ethyl=CH2CH3. Add these as prefixes to the longest chain, numbering so that you get the lowest total number.
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    (Original post by LearningMath)
    Having written them out, i can see 4) should be: 4-ethyl-2,3-methylhexane. It is ethyl before methyl right shengoc?
    hmm, never know that i could pass my a level organic chem without knowing this, but yeah, I think you are right, alphabetical order, so ethyl before methyl, just like butyl before ethyl.

    but yeah, feel free to correct me, this is really not my strongest area, perhaps i should stay away; :confused:
 
 
 
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