Qualification > Sciences
ALL CIE CHEMISTRY DOUBTS HERE !!
Amii:
--- Quote from: Ari Ben Canaan on February 04, 2011, 11:00:59 am ---Questions 23,26,29 and 30
--- End quote ---
26) B-CH3CHBRCH=CH2 has identical atoms attached to one of the carbon atoms in the double bond- so no cis-trans in this compound.
A,B,D - exhibits cis-trans isomerism.
But only D has a Carbon atom which has 4 different atoms/groups attached to it - hence only D will can show optical isomerism.
I hope it makes sense. :-[
Amii:
--- Quote from: Ari Ben Canaan on February 04, 2011, 11:00:59 am ---Questions 23,26,29 and 30
--- End quote ---
29)D (CH3)3CBr
-Tertiary halogenoalkane.
-Undergoes hydrolysis by SN1 mechanism.
-Reaction takes place in two steps.
-Since the rate determining step doesn't involve the nucleophile,changing the concentration of OH- doesn't affect the rate of the SN1 reaction.
Amelia:
--- Quote from: Ari Ben Canaan on February 05, 2011, 11:45:44 am ---I've identified the chiral centres by drawing a red square next to them.
Am I correct ?
--- End quote ---
Yes.
The answer to 23 is C.
elemis:
In the first one, why isnt the answer D ?
Reduction is the GAIN of Hydrogen, right ? In step 2 a massive molecule is added that has several hydrogens. Isnt this reduction ?
Can you explain why the answer is C ?
In the second one, I have marked the chiral centre. Is it correct ?
Amelia:
^ There are three methyl groups in 2,2dimethylbutane. Available for Chlorine radicals to attack on. So free radicals are formed from each Ch3's.
--- Quote ---In the second one, I have marked the chiral centre. Is it correct ?
--- End quote ---
Yes, it is.
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