Explain why NH3 is basic while BiH3 is only feebly baisc?
Explain why NH3 is basic while BiH3 is only feebly baisc?
NH3 is distinctly basic while BiH3 is feebly basic.
Nitrogen has a small size due to which the lone pair of electrons is concentrated in a small region. This means that the charge density per unit volume is high. On moving down a group, the size of the central atom increases and the charge gets distributed over a large area decreasing the electron density. Hence, the electron donating capacity of group 15 element hydrides decreases on moving down the group.
The atomic size of nitrogen (atomic radius= 70 pm) is less than that of bismuth (atomic radius =148 pm). As a result, electron density on the nitrogen atom is greater than that on Bismuth atom. It means that an electron releasing tendency of ammonia is more than BiH3. Therefore, NH3 is basic while BiH3 is only feebly basic.
Note Atomic size will be considered while comparing the basicity of NH3 with other hydrides of group 15 elements.
NH3 is distinctly basic while BiH3 is feebly basic.
Nitrogen has a small size due to which the lone pair of electrons is concentrated in a small region. This means that the charge density per unit volume is high. On moving down a group, the size of the central atom increases and the charge gets distributed over a large area decreasing the electron density. Hence, the electron donating capacity of group 15 element hydrides decreases on moving down the group.
The atomic size of nitrogen (atomic radius= 70 pm) is less than that of bismuth (atomic radius =148 pm). As a result, electron density on the nitrogen atom is greater than that on Bismuth atom. It means that an electron releasing tendency of ammonia is more than BiH3. Therefore, NH3 is basic while BiH3 is only feebly basic.
Note Atomic size will be considered while comparing the basicity of NH3 with other hydrides of group 15 elements.
