Question

In CH₄, NH_3, and H₂O, the central atom undergoes sp3 hybridization – yet their bond angles are different. Why?

Answer 1

According to VSEPR theory, as H₂O has two lone pairs so it repels the bond pairs much more and makes the bond angle shorter of 104.5 degrees, and as NH₃ has one lone pair that repels the three bond pairs but not much effectively and strongly as two lone pairs of water repel one bond pair.

So the bond angle between the Hydrogen atom of ammonia is 107.5 greater than that of water. Similarly, methane molecules have no lone pair and bond pair repels each other with an equal bond angle between two adjacent hydrogen atoms becomes 109°.28′.