Question

A central atom in a molecule has two lone pairs of electrons and forms three single bonds. The shape of the molecule is:

• A. Trigonal pyramidal
• B. T-shaped
• C. See-saw
• D. Planar triangular

Answer 1

The correct option is B

T-shaped

Answer: B

Explanation for correct option:

(B) T-shaped molecule geometry is made up of $5{\mathrm{sp}}^3\mathrm{d}$ hybrid orbitals. Three are arranged around of equator of the molecule with the bond angle of $120°$.Two orbitals are arranged along the vertical axis at $90°$ from the equatorial orbitals

Examples: ${\mathrm{ClF}}_3,{\mathrm{BrF}}_3,{\mathrm{XeF}}_2$etc

Explanation for incorrect options:

(C) Trigonal pyramidal is a molecule shape that results when there are three bonds and one lone pair on the central atom in the molecule. Molecules with tetrahedral electron pair geometries have ${\mathrm{sp}}^3$ hybridization at the central atom.

Example::${\mathrm{NH}}_3$etc

(C) See saw is a type of molecular geometry in which four bonds connect to the central atom, resulting in an overall ${\mathrm{C}}_{2\mathrm{v}}$molecular symmetry. "The name See saw " is derived from the fact that it resembles a playground seesaw.

Example:${\mathrm{SF}}_4,{\mathrm{IF}}_4^{+},{\mathrm{TeCl}}_4$

(D) Planar Triangular compound has a central atom attached to three atoms arranged in a triangular shape around the central atom. All four atoms lie flat on a plane (${\mathrm{sp}}^2$)

Example:${\mathrm{CO}}_3^{2-},{\mathrm{SO}}_3,{\mathrm{COCl}}_2$

Hence option (B) is the correct answer