Question

Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R.
Assertion A : The H–O–H bond angle in water molecule is ${104.5}^o$.
Reason R : The lone pair–lone pair repulsion of electrons is higher than the bond pair-bond pair repulsion.

• A. A is false but R is true
• B. Both A and R are true, but R is not the correct correct explanation of A
• C. A is true but R is false
• D. Both A and R are true, and R is the correct explanation of A

Answer 1

The correct option is D Both A and R are true, and R is the correct explanation of A

The hybridisation of oxygen is water molecule is $s{p}^3$, so electron geometry of water molecule is tetrahedral and the bond angle should be 109°28" but as we know that lone pair-lone pair repulsion of electrons is higher than the bond pair-bond pair repulsion because lone pair is occupied more space areound central atom than that of bond pair. Thus, its bond angle becomes ${104.5}^o$.


Hence, option (d) is correct.