How does the presence of the lone pair affect the geometry of the central atom in the following molecule?
I The lone pair is attracted to the nuclei of the three substituents,creating larger bond angles.
II The lone pair repels the three sets of covalently bonded electrons.
III The lone pair has no bearing whatsoever on the VSEPR geometry at the central atom.
IVThe bond angles are smaller than a traditional tetrahedral bond angle due to lone pair repulsion.

Question

How does the presence of the lone pair affect the geometry of the central atom in the following molecule? 
I The lone pair is attracted to the nuclei of the three substituents,creating larger bond angles.
II The lone pair repels the three sets of covalently bonded electrons.
III The lone pair has no bearing whatsoever on the VSEPR geometry at the central atom.
IVThe bond angles are smaller than a traditional tetrahedral bond angle due to lone pair repulsion.

Quizplus · Accepted Answer

The lone pair in the molecule will repel the three sets of covalently bonded electrons, leading to smaller bond angles than a traditional tetrahedral bond angle. This is known as the "lone pair effect". Therefore, option II is correct. Additionally, this effect will lead to larger bond angles between the substituents, as the lone pair is attracted to the nuclei of the substituents, which is described in option I. Therefore, E is the best choice.

How Does the Presence of the Lone Pair Affect the Geometry