Question

Why basic character of hydrides of group 15 decrease down the group?

Answer 1

Bases are those compound which have a tendency to donate electron. Hence the term, Lewis base.

In group 15 , the hydrides of the formula XH3 have a lone pair on the central atom . As we go down the group, size of the atom increases. Hence electron density over the group 15 decreases.

That's why the tendency to donate electron decreases, hence basicity decreases down the group.

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