Alcohols donot react with NaBr but when H.SO, is added they form alkyl bromides. Explain.

Explanation

Although `Br^(-)` is a strong nucleophile yet `OH^(-)` being a strong base is a bad leaving group. Therefore, `Br^(-)` cannot displace `OH^(-)` from ROH to form R-Br. In other words, NaBr does not react with alcohols. however, when `H_(2)SO_(4)` is added, protonation of alcohol occurs, i.e., -OH is converted into `-overset(+)(O)H_(2)`. since `H_(2)O` is a very weak base, therefore, it is a good leaving group. in otehr words, `Br^(-)` cann displace `H_(2)O` from protonated alcohol to form RBr.
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