Question

Determine whether each molecule given below is polar or nonpolar.

CF4    PBr5    XeF2    SF6   

Answer 1

Concepts and reason

The concept used to solve this problem is based on polarity of a molecule.

The polarity is the property of a molecule which arises due separation of electric charge. Due to this separation of charges molecule exhibit dipole moment which means one end of molecule accommodates slightly positive charge and another end accommodates slightly negative charge.

Fundamentals

The dipole moment for polar molecules is non-zero and non-polar molecule is zero.

In a polar molecule, electronegativity of their atoms is not equal. In a non-polar molecule, electronegativity of their atoms is equal.

Part 1

In ${\rm{C}}{{\rm{F}}_4}$ , although there is a difference between electronegativity of fluorine and carbon but due to its tetrahedral structure ${\rm{C}}{{\rm{F}}_4}$ has zero dipole moment. It is a non-polar molecule.

Part 2

In ${\rm{P}}{{\rm{B}}_5}$ , although there is a difference between electronegativity of bromine and phosphorous but due to its trigonal bipyramidal structure ${\rm{P}}{{\rm{B}}_5}$ has zero dipole moment. It is a non-polar molecule.

Part 3

In ${\rm{Xe}}{{\rm{F}}_2}$ , although there is a difference between electronegativity of fluorine and xenon but due to its linear structure ${\rm{Xe}}{{\rm{F}}_2}$ has zero dipole moment. It is a non-polar molecule.

Part 4

In ${\rm{S}}{{\rm{F}}_6}$ , although there is a difference between electronegativity of fluorine and sulfur atom but due to its octahedral structure ${\rm{S}}{{\rm{F}}_6}$ has zero dipole moment. It is a non-polar molecule.

Ans: Part 1

The molecule ${\rm{C}}{{\rm{F}}_4}$ is non-polar.

Part 2

The molecule ${\rm{P}}{{\rm{B}}_5}$ is non-polar.

Part 3

The molecule ${\rm{Xe}}{{\rm{F}}_2}$ is non-polar.

Part 4

The molecule ${\rm{S}}{{\rm{F}}_6}$ is non-polar.