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Organic Chemistry

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11 Mar 2010 21:20:38 IST

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sir, what is markonikaff's rule?

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sir, what is markonikaff's rule?

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snehil PRAKASH

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11 Mar 2010 21:26:19 IST

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The rule states that with the addition of a protic acid HX to an alkene, the acid hydrogen (H) becomes attached to the carbon with fewer alkyl substituents, and the halide (X) group becomes attached to the carbon with more alkyl substituents

SUNIL KHORWAL

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13 Mar 2010 11:55:02 IST

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The same is true when an alkene reacts with water in an addition reaction to form alcohol. The hydroxyl group (OH) bonds to the carbon that has the greater number of carbon-carbon bonds, while the hydrogen bonds to the carbon on the other end of the double bond, that has more carbon-hydrogen bonds.The chemical basis for Markovnikov's Rule is the formation of the most stable carbocation during the addition process. The addition of the hydrogen to one carbon atom in the alkene creates a positive charge on the other carbon, forming a carbocation intermediate. The more substituted the carbocation (the more bonds it has to carbon or to electron-donating substituents) the more stable it is, due to induction and hyperconjugation. The major product of the addition reaction will be the one formed from the more stable intermediate. Therefore, the major product of the addition of HX (where X is some atom more electronegative than H) to an alkene has the hydrogen atom in the less substituted position and X in the more substituted position. However, the other less substituted, less stable carbocation will still be formed to some degree, and will proceed to form the minor product with the opposite attachment of X.The rule may be summarized as "the rich get richer and the poor get poorer": a carbon rich in substituents will gain more substituents and the carbon with more hydrogens attached will get the hydrogen in many organic addition reactions.

GamE

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14 Mar 2010 11:15:10 IST

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THE NEGATIVE PART OF THE ADDENDUM GETS ATTACHED TO THE CARBON BEARING LEAST NO. OF HYDROGEN ATOMS----This is Markonikov's rule

GamE

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14 Mar 2010 11:16:46 IST

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pls rate me

Krishna Murthy

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14 Mar 2010 11:38:57 IST

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SIMPLE WAY!!!! REMEMBER THESE WORDS. POOR BECOMES POORER!!!!!!! (with respect to Hydrogen),i.e., positive part(Hydrogen) goes to carbon which has more Hydrogen atoms already

Madhusudan Chavan

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14 Mar 2010 12:00:12 IST

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The addition of an unsymmetrical reagent such as HX, H2O, HOX, etc. to unsymmetrical alkenes occurs in such a way that the negative part of the addiding molecule goes to that carbon atom of the double bond which carries lesser number of hydrogen atoms.

markovnilov's addition occurs through more stable carbocation intermediate.

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