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What is relative basic strength order 1° amines , 2°amines and 3° amines ? Explain:

Amines are more basic in nature than ammonia because in amines alkyl groups are present, which have +I effect, therefore. They increase electron density on nitrogen atom; therefore, amines can donate electron pair more easy than ammonia. On the basis above conclusion the expected order of basic nature of amines is 3°amine > 2°amine > 1° amine (basis of Inductive effect) in gaseous state) 

But actual order is 2° amine > 1°amine > 3°amine this anomalous behavior of amines is explained as follows:
 Actually basic nature of amines not only depends upon electron density available on nitrogen atom, but also depends upon stability of conjugate acid (Solvation effect) that amines form in aqueous solutions. The stability of conjugate acid in turn depends upon the extent of hydrogen bonding. Greater the extent of hydrogen bonding stronger is the conjugate acid and more is the basic nature of amines. on the basis of stability of conjugate acid (Solvation effect) the expected order of basic nature of amines is 1° amine > 2°amine 3°amine 

But net result of the two opposing factors (Inductive and Solvation effect) the net  basic strength order is as 2°amime > 1° amine > 3°amine.

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