Question

Which of the statements given below are true for the structure of water molecule?
(i) Oxygen undergoes $s{p}^3$ hybridization.
(ii) Due to the presence of two lone pairs of electrons on oxygen, the $H-O-H$ bond angle is ${118.4}^0$
(iii) Due to angular geometry the net dipole moment of water is not zero, u = 1.84 D.

• A. (i) and (ii)
• B. (ii) and (iii)
• C. (i) and (iii)
• D. only (ii)

Answer 1

The correct option is C (i) and (iii)

$H-O-H$ angle in water is slightly less than the typical tetrahedral angle. It is ${104.5}^o$. If all the substituents were the same (such as in $C{H}_4$), the bond angle would be ${109.5}^o$. In water, $H-O-H$ bond angle decreases from ${109.5}^o$ to ${104.5}^o$ as lone pair-lone pair repulsion is more than bond pair-bond pair repulsion and lone pair-bond pair repulsion.