question_answer

Hybridisation of the underline atom changes in   AIEEE  Solved  Paper-2002

A) \[\underline{A}\,l{{H}_{3}}\] changes to \[\underline{A}\,lH_{4}^{-}\]

B) \[{{H}_{2}}\underline{O}\] changes to \[{{H}_{3}}{{O}^{+}}\]

C) \[\underline{N}{{H}_{3}}\] changes to \[NH_{4}^{+}\]

D) in all the above cases

Correct Answer: A

Solution :

	\[Al{{H}_{3}}\] \[s{{p}^{2}}\]		Change in hybridization as well as in shape
	\[{{H}_{2}}O\] \[s{{p}^{3}}\] \[(2\,bp+2\,lp)\]	\[{{H}_{3}}{{O}^{+}}\] \[s{{p}^{3}}\]\[(3\,bp+1\,lp)\]	Change in shape only, bent to pyramidal
	\[N{{H}_{3}}\] \[s{{p}^{3}}\] \[(3\,bp+1lp)\]	\[NH_{4}^{+}\] \[s{{p}^{3}}\] \[(4\,bp)\]	Change in shape only, pyramidal to tetrahedral