Chemistry - CHEMICAL BONDING Question with Solution | TestHub
The simplest boron hydride known is diborane (B₂H₆). As implied by the mechanism of hydrolysis, diborane and many other light boron hydrides act as Lewis acids, and they are cleaved by reaction with Lewis bases. Two different cleavage patterns have been observed: symmetric cleavage and unsymmetric cleavage.
In symmetric cleavage, B₂H₆ is broken symmetrically into two BH₃ fragments with NMe₃. While with NH₃, MeNH₂, MeNH₂ results in unsymmetrical cleavage, which is a cleavage leading to an ionic product.
What is the bond angle present in the anionic part of "X"?
Answer:
Solution:
The reaction between diborane (B₂H₆) and ammonia (NH₃) involves unsymmetrical cleavage to form the ionic product "X", which is . The anionic part of this compound is the borohydride ion, . In , the central boron atom undergoes sp³ hybridization to bond with four hydrogen atoms. This results in a perfect tetrahedral geometry for the anion, as there are no lone pairs to cause distortion. The ideal bond angle for a regular tetrahedron is .