Question

(A) Explain VSEPR theory with suitable example.​

Answer 1

Answer:

VSEPR theory explain the shape of a molecule by number of valence electron present in valence shell of central atom. Charged electrons in valence shell repel each other, electrons occupy such position in space so that repulsion should be minimum.

Explanation:

BOND PAIR - DEFINITION

The pair of electrons involved in bond formation is called as bond pair electron and the pair of electron which is not involved in bond formation but remain present on atom, in molecule is called as lone pair of electron. For example: ammonia molecule, it contain 3 bond pair of electrons and 1 lone pair of electrons.

Answer 2

VSEPR theory is also known as valency shell electron pair repulsion theory.

Explanation:

• VSEPR theory was given by Sidwick and Powell in 1940.
• This theory helps to determine the shape of the molecules which is surrounded by central atoms.

VSEPR postulates are as follows

• The number of valence shell electron pairs helps to decide the shape of the molecule.
• In polyatomic molecules, constituent atoms are identified as the central atom to this other atoms are linked.
• This theory can be applied to the resonance structure.
• The Central atom should be surrounded by lone pairs and bond pairs of electrons which leads to distorted shape.

• The Central atom should be surrounded by bond pairs of electrons which leads to asymmetrically shaped molecule.

• The strength of repulsion will be strongest in lone pairs and weakest in bond pairs.
• Few examples

Linear shape BeF2

Trigonal Bipyramidal BF3

Tetrahedral CH4