The states of hybridization of boron and oxygen atoms in boric acid ($\mathrm{H}_{3}\mathrm{BO}_{3}$) are respectively

(A) $\mathrm{sp}^{2}$ and $\mathrm{sp}^{2}$

JEE Main · 2004 · 24 Apr 2004 · Offline · Chemical Bonding and Molecular Structure

The states of hybridization of boron and oxygen atoms in boric acid (

H_{3} BO_{3}

) are respectively

Answer: (D)

In boric acid

H X_{3} BO X_{3}

the boron sits at the centre of three oxygen atoms in a flat, trigonal arrangement with no lone pair on boron, which is

s p^{2}

hybridisation. Each oxygen is bonded to boron and to hydrogen and still holds two lone pairs, giving it four electron domains and

s p^{3}

hybridisation. So boron is

s p^{2}

while oxygen is

s p^{3}

JEE Main · 2004 · 24 Apr 2004 · Offline · Single correct option