[Aravind]

well i have been seeing in my organic text that sometimes the compounds are written backwards like CH3Br as BrCH3 at some place .are they representing the same idea of molecule? DOES IT MATTER how i write the compund starting in left?I am confused i cant get to a final decision please help

[zeved]

no, it does not matter. however I only see stuff written backwards in drawings (such as http://en.wikipedia.org/wiki/File:Trinitrotoluene.svg - left side - O₂N) where I suppose they want to make clear what atom is bonded to what.. even if it's obvious

[Arkcon]

There are conventions on how you should write compounds, and according to strict IUPAC naming, strict rules.  So in your example, it should be CH₃.  However, sometimes when we draw a molecule, and want to show a reaction mechanism, its a little bit clearer to diagram the name a little bit differently.

[Aravind]

in my text wurtz reaction is written like this :;

CH3Br +2Na +BrCH3 gives CH3-CH3 +2NaBr

so can i write 2 CH3Br on left ??

[Borek]

so can i write 2 CH3Br on left ??

Yes. The way it is written it is putting emphasis on the mechanism (easy to see what and how is expected to combine), but there is nothing wrong with writing it as

2CH₃Br + 2Na  C₂H₆ + 2NaBr

[Aravind]

thanks a lot!!.this doubt was in myy mind for about 1 and a half year!!