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ALL CIE CHEMISTRY DOUBTS HERE !!

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moon:
can somebody plz explain Q5 d,Q8 b(ii),c & Q9a(i) in June 2009 ppr4

I would appreciate ur help, thanx in advance.

Deadly_king:

--- Quote from: moon on October 13, 2010, 01:00:10 am ---can somebody plz explain Q5 d,Q8 b(ii),c & Q9a(i) in June 2009 ppr4

I would appreciate ur help, thanx in advance.

--- End quote ---

Jun 09 p4 No 5

Hmmm......part (d) will depend on the alcohols you drew in part (a).

If it is a primary alcohol, the latter will get oxidised to a carboxylic acid.

If it is a secondary alcohol, it will get oxidised to a ketone.

If it is a tertiary alcohol, it will not get oxidised. (stays the same)

However you won't be having any tertiary alcohols, since the question asks for unbranched compounds.

moon:

--- Quote from: Deadly_king on October 13, 2010, 12:06:33 pm ---Jun 09 p4 No 5
If it is a tertiary alcohol, it will not get oxidised. (stays the same)

--- End quote ---

Do u mean that teertiary alcohol on oxidation will be a tertiary alcohol and not ketone????????????? because the markscheme's answer was CH3CH2COCH2CH3

Deadly_king:

--- Quote from: moon on October 13, 2010, 12:21:54 pm ---Do u mean that teertiary alcohol on oxidation will be a tertiary alcohol and not ketone????????????? because the markscheme's answer was CH3CH2COCH2CH3

--- End quote ---

Yeah.........but the compound you drew is not a tertiary alcohol. It is a secondary one. That's why it gets converted into a ketone.

NOTE : A tertiary alcohol is one whose OH group is bonded to a carbon atom which is already bonded to three other carbon atoms. In other words the carbon atom is not attached to any hydrogen atom ;)

P.S : I edited my previous post. Do have a look, it might clear your doubt.

moon:
Thanks 4 ur explanation but can u explain me why the partition coefficient between fat & water for PCB residues in Q8 b(ii) is greater than 1???? Thanks 4 ur cooperation..

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