Question

Orthoboric acid contains :

• A. Pyramidal $B{O}_3^{3-}$ units
• B. .Linear $B{O}_3^{3-}$ units
• C. T-shaped $B{O}_3^{3-}$ units
• D. Triangular $B{O}_3^{3-}$ units

Answer 1

The correct option is D Triangular $B{O}_3^{3-}$ units

The simplest borate anion, the orthoborate ion, ${B{O}_3}^{3-}$ is known. In this it adopts a near trigonal planar structure. It is a structural analogue of the carbonate anion ${C{O}_3}^{2-}$, with which it is isoelectronic. Simple bonding theories point to the trigonal planar structure. In terms of valence bond theory the bonds are formed by using $s{p}^2$ hybrid orbitals on boron as shown in figure.