RCOOAg in presence of Br2​/heat gives RBr.
​Which of the following acid will give maximum yield of RBr in above reaction 
a) CH3CH(CH3)COOH
​b) CH3CH2CH2COOH
​c) CH3C(CH3)2​COOH
d) all will give same yield

Dear Student,

This reaction is Hundiecker reaction which occurs via free radical mechanism. Lesser the stability of the free radical, more will be the yield of the reaction.This is because, less stable radical will be the most reactive and so will form alkyl halide more quickly and as a result yield will be higher. 
Order of stability of free radicals : Primary < Secondary < Tertiary
Therefore, increasing order of yield : Tertiary < Secondary <Primary

In(a) secondary free radical will be formed
In (b) primary free radical will be formed
In (c) tertiary free radical will be formed.

Therefore, (b) will give maximum yield. 
 

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