Question
Question: Among the following species, identify the isostructural pairs. \(N{F_3}\), \(NO_3^ - \), \(B{F_3}\...
Among the following species, identify the isostructural pairs.
NF3, NO3−, BF3, H3O+,HN3
A.[NF3,NO3−] and [BF3,H3O+]
B.[NF3,HN3] and [NO3−,BF3]
C.[NF3,H3O+] and [NO3−,BF3]
D.[NF3,H3O+] and [HN3,BF3]
Solution
To find the isostructural species among the given compounds, we must find the hybridisation of the central atom of each species and the arrangement of the bond pairs and lone pairs on the central atom. To do that, you must recall the VSEPR (Valence shell electron pair repulsion) theory. It suggests that all valence shell electron pairs surrounding the central atom arrange themselves in such a manner so as to be as far away from each other as possible.
Complete step by step solution:
The species which have similar chemical structures are known as isostructural chemical compounds.
Considering NF3 : We know that nitrogen has five valence electrons. In the given compound nitrogen is forming three bonds with fluorine atoms. Thus, nitrogen has three bond pairs and one lone pair. Its hybridisation is sp3 and the shape is pyramidal.
Considering NO3− : Nitrogen has five valence electrons. The compound carries one negative charge and nitrogen is making four bonds with oxygen atoms, out of which one is a double bond. The hybridisation is sp2 and shape is triangular planar
Considering BF3 : Boron has three valence electrons and forms a single bond with each fluorine atom. The hybridisation is sp2 and the shape is triangular planar
Considering H3O+ : oxygen has six valence electrons. It forms two covalent bonds with two hydrogen atoms and a coordinate bond with the third hydrogen. In total, it has three bond pairs and a lone pair. The hybridisation is sp3 and the shape is pyramidal.
NF3 and H3O+ are isostructural and NO3− and BF3 are isostructural.
Thus, the correct answer is option (C).
Note: During bond formation, the atomic orbitals of an atom are mixed in such a manner as to produce equivalent orbitals. This mixing of orbitals is known as hybridisation. The arrangement of these hybrid orbitals according to the VSEPR theory gives us the shape of the molecule.