question_answer 80)

  Alcohols react with active metals, e.g., Na, K, etc. to give corresponding alkoxides. Write down the decreasing order of reactivity of sodium metal towards primary, secondary and tertiary alcohols.

Answer:

                  Alkyl groups have +I-effect. As the number of alkyl groups increases from 1 to 2 to 3 in going from 1° to 2° to 3° alcohols, the electron density in the O?H bond increases and the bond becomes stronger and stronger. In other words, acidic character of alcohols decreases from 1° to 2° > 3°. Since Na metal is basic and alcohols are acidic in nature, therefore, reactivity of Na metal towards alcohols decreases as the acidic strength of alcohols decreases, i.e., in the order : 1° > 2° > 3°.