Question
Chemistry Question on Alcohols, Phenols and Ethers
Decreasing order of reactivity of hydrogen halide acids in the conversion of ROH→RX is
A
HCl>HBr>HI>HF
B
HI>HBr>HCl>HF
C
HF>HCl>HBr>HI
D
HF>HBr>HI>HCl
Answer
HI>HBr>HCl>HF
Explanation
Solution
Since the conversion of an alcohol to alkyl halide is an nucleophilic substitution reaction and the nucleophilicity (ie, tendency to donate an electron pair to the carbon atom) of the halide ions decreases in the order, I−>Br−>Cl−>F− , Thus, the order of reactivity of halogen acids decreases in order : HI>HBr>HCl>HF .