Chapter 11, Problem 15STP

Interpretation Introduction

Interpretation:

The trigonal planar molecular shape needs to be identified.

Concept introduction:

The molecular shape of the molecule depends on the number of bonds and the lone pair of electrons present in the molecule. The total number of valence electrons decides the hybridization of the central atom thus, the molecular geometry. The number of lone pairs decides the molecular shape which is different from molecular geometry due to lone pair-bond pair repulsion.

Answer to Problem 15STP

Correct Answer: Option B.

Explanation of Solution

Reason for correct option:

The given molecule B has 3 bond pairs of electrons. The central atom will be sp² hybridized. Thus, the molecular geometry will be trigonal planar. Due to the absence of a lone pair of electrons, the molecular shape will be trigonal planar.

Conclusion

Reason for incorrect option:

The given molecule A has 2 lone pairs of electrons and 2 bond pairs of electrons. Thus, the total number of pairs of valence electrons will be 4. The molecule will be sp³ hybridized. The molecular geometry will be tetrahedral. Due to the presence of 2 lone pairs of electrons, the molecular shape will be bent.

The given molecule C has 4 bond pairs of electrons. The molecule will be sp³ hybridized. The molecular geometry will be tetrahedral. Due to no lone pair of electrons, the molecular shape will also be tetrahedral.

The given molecule D has 2 bond pairs of electrons. The molecule will be sp hybridized. The molecular geometry will be linear. Due to the zero lone pair of electrons, the molecular shape will also be linear.

The given molecule E has 3 bond pairs of electrons and 1 lone pair of electron. The molecule will be sp³ hybridized. The molecular geometry is tetrahedral. Due to the presence of 1 lone pair of the electron, the molecular shape is trigonal pyramidal.