Question

how would you account for the difference in bond angles in h2o(104.5) and ch4 (109.5) when oxygen and carbon are sp3 hybridized?

Answer 1

Answer:

In CH4, there are four H atoms bonded with a C atom. Hence bong angle is same between all of the (=109.5°).

In H2O, there are two H atoms bonded with O atom and two lone pairs of the O atom. The lone pair electrons push the two H atoms away. Hence the bond angle between the H atoms decreases (=104.5°) while the bond angle between the Lone pairs and H atoms increase (>109.5°).

Hope it helps you.