The H — C — H bond angle in CH4 is 109.5°, due to lone pair repulsion, the H — O — H angle in H2O wi — Chemical Bonding Chemistry Question

💡 Solution & Explanation

Step 1: Methane (CH4) has 4 bond pairs and 0 lone pairs on carbon, giving it a regular tetrahedral shape with a bond angle of 109.5°. Step 2: Water (H2O) is also based on a tetrahedral electron geometry (sp3 hybridization) but contains 2 bond pairs and 2 lone pairs on oxygen. Step 3: Because lone pair-lone pair repulsions are stronger than bond pair-bond pair repulsions, the lone pairs compress the H-O-H bond angle, causing it to decrease to ~104.5° (option c).