The acidic strength for the hydrides of group 15 follows the order

Options

A. `NH _(3) lt PH _(3)lt AsH _(3) lt SbH_(3)`
B. `NH _(3) gt PH _(3)gt AsH _(3) gt SbH_(3)`
C. `NH _(3) gt PH _(3)gt SbH _(3) gt AsH_(3)`
D. `NH _(3) lt PH _(3)lt AbH _(3) lt AsH_(3)`

Answer

B

Explanation

The acidic strength of hydrides is inversely proportional to their stability. Since the stability of hydrides decreases from N to Sb. Therefore, the acidic strength increases from N to Sb. Hence, the correct order would be
`NH _(3) lt PH _(3) lt As H _(3) lt Sb H _(3)`
Caution point
As the stability decreases from `NH _(3)` to `BiH _(3),`reducing character of hydrides increases.