Question

Explain what is VSEPR theory.

Answer 1

Valence shell electron pair repulsion (VSEPR) theory is used to predict the molecular shapes of various molecules from the electron pairs that surround the central atoms of the molecule.
Some pairs of the valence electrons take part in covalent bond formation are called bond pairs. While some pairs of electrons do not participate in any bond formation, hence called lone pairs.
The theory states that the electron pairs arrange themselves in such a way that they minimize the repulsion between them.

Decreasing order of repulsions between electron pairs are:
lone pair-lone pair > lone pair-bond pair > bond pair-bond pair.

Some examples of VSEPR model of molecules are:

1. Water (Bent shape)



2. Ammonia (Trigonal pyramidal)


3. Boron trifluoride (Trigonal planar)