Question

Assertion (A): Though the central atom of both \[\ce{NH3}\] and \[\ce{H2O}\] molecules are sp³ hybridised, yet \[\ce{H -N - H}\] bond angle is greater than that of \[\ce{H - O - H}\].

Reason (R): This is because nitrogen atom has one lone pair and oxygen atom has two lone pairs.

Options

• A and R both are correct, and R is the correct explanation of A.

• A and R both are correct, but R is not the correct explanation of A.

• A is true but R is false

• A and R both are false.

Answer 1

A and R both are correct, and R is the correct explanation of A.

Explanation:

In \[\ce{NH3}\] only one lone pair of electron is present and due to that lone pair-bond pair repulsion occurs which forms a distorted tetrahedral geometry (pyramidal). In \[\ce{H2O}\] two lone pairs of electrons are present on the oxygen atom and due to this lone pair-lone pair repulsion occurs which shifts the bonds and forms a bent geometry. The lone pair-lone pair repulsion is more than the lone pair-bond pair repulsion. Thus, bond angle in \[\ce{H - N - H}\] is more than that of  \[\ce{H - O - H}\].