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ALL CIE CHEMISTRY DOUBTS HERE !!

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Amelia:

--- Quote from: Ari Ben Canaan on February 08, 2011, 02:41:52 pm ---I know the carbon with the red square is DEFINITELY chiral. Why is the one with the PINK square  NOT chiral ?

--- End quote ---

It actually has three chiral's. The pink one you marked is a chiral as well. And also, the first Carbon. (CH-CH3)


--- Quote from: Ari Ben Canaan on February 08, 2011, 02:44:27 pm ---I dont understand. Are you talking about the right question ?

--- End quote ---

Mistook your question. I apologize.

elemis:
Last question, (e) part.

I drew the following compound, yet the markscheme shows something else altogether.

Would my answer be accepted ?

Deadly_king:

--- Quote from: Ari Ben Canaan on February 17, 2011, 04:37:02 am ---Last question, (e) part.

I drew the following compound, yet the markscheme shows something else altogether.

Would my answer be accepted ?

--- End quote ---

Sorry for lateness but I had to do the whole number to get the required answer.

So your answer will NOT be accepted. Tests 5 and 6 eliminates your answer completely. Now I'll explain :

For the compound you drew, upon test 5, it would get oxidised to a carbon dioxide and a carboxylic acid as the C=C will break. So the resulting carboxylic acid will give a positive result with the following test.(test 6)

Hence your answer is rejected.

elemis:

--- Quote from: Deadly_king on February 17, 2011, 05:15:36 am ---Sorry for lateness but I had to do the whole number to get the required answer.

So your answer will NOT be accepted. Tests 5 and 6 eliminates your answer completely. Now I'll explain :

For the compound you drew, upon test 5, it would get oxidised to a carbon dioxide and a carboxylic acid as the C=C will break. So the resulting carboxylic acid will give a positive result with the following test.(test 6)

Hence your answer is rejected.



--- End quote ---

2,4-DNPH gives a positive result only with Aldehydes or Ketones not Carboxylic acids.

Deadly_king:

--- Quote from: Ari Ben Canaan on February 17, 2011, 05:25:48 am ---2,4-DNPH gives a positive result only with Aldehydes or Ketones not Carboxylic acids.

--- End quote ---

That's true but before turning into a carboxylic acid......the compound will first be converted into an aldehyde. We need to oxidise much more for it to get converted to carboxylic acid.

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