Question

What is the molecular geometry of AsCl₃?

T-shaped

tetrahedral

trigonal planar

trigonal pyramidal

Answer 1

Concepts and reason

Valence Shell Electron Pair Repulsion (VSEPR) Theory: In Chemistry, VSEPR is a tool used to identify the geometry around the central atom, which is surrounded by pairs of electrons (bond and lone pairs). It is predicted only by repulsions between electron pairs present in the central atom.

Fundamentals

VSEPR Chart:

The order of decreasing repulsive interactions between electron pairs is given below:

Lone pair – lone pair  lone pair – bond pair  bond pair – bond pair

The incorrect choices in the given problem are given below:

• T-shaped: It is an incorrect choice because it has five electron pairs around the central atom.

• Tetrahedral: It is an incorrect choice because it has only four electron pairs without a lone pair around the central atom.

• Trigonal Planar: It is an incorrect choice because it has only three electron pairs around the central atom.

The given compound is .

The number of valence electrons in the central atom () is 5.

The number of lone pair electrons around the central atom is 1.

The number of bonds around the central atom is 3.

The total number of pairs of electrons around the central atom is 4.

According to VSEPR theory:

Hence, the molecular geometry is trigonal pyramidal.

Ans:

The correct molecular geometry is marked with a tick mark as follows: