question_answer

Which of the following molecules has pentagonal bipyramidal shape?

A) \[P{{F}_{5}}\]                                    

B) \[S{{F}_{6}}\]

C) \[Xe{{F}_{6}}\]                 

D) \[{{[Fe{{(CN)}_{6}}]}^{3-}}\]

Correct Answer: C

Solution :

In the formation of \[Xe{{F}_{6}}\] molecule, three \[5p\] electrons are promoted to \[5d\] orbitals. Now, one\[5s\], three \[5p\] and three 5d orbitals of \[Xe\] atom intermix together and form seven \[s{{p}^{3}}{{d}^{3}}\] hybrid orbitals. One \[s{{p}^{3}}{{d}^{3}}\] hybrid orbital contains one lone pair of electrons while other six are half-filled. The expected geometry is pentagonal bipyramidal.