Identify each of the following molecules as polar or nonpolar:
a. ${\mathrm{CS}}_2$
b. ${\mathrm{NF}}_3$
c. ${\mathrm{CHF}}_3$
d. ${\mathrm{SO}}_3$

We have to identify that ${\mathrm{CS}}_2$molecule is polar or nonpolar.

The ${\mathrm{CS}}_2$ molecule is a nonpolar molecule.
Because of the molecule's linear nature.The $\mathrm{C}-\mathrm{S}$ bond has a small dipole moment.

We have to identify that ${\mathrm{NF}}_3$molecule is polar or nonpolar.

${\mathrm{NF}}_3$ is polar molecule.
The $\mathrm{N}$is somewhat positive and the $\mathrm{F}$is partially negative in polar $\mathrm{N}-\mathrm{F}$ bonds.
The molecule is slightly assymetric with regard to the negative centres around the $\mathrm{N}$atom due to the lone pair of electrons on the $\mathrm{N}$ atom (VSEPR theory)
The $\mathrm{N}-\mathrm{F}$bonds' dipole moments do not cancel out, resulting in a dipole moment that makes the molecule polar.

We have to identify that ${\mathrm{CHF}}_3$molecule is polar or nonpolar.

The chemical trifluoromethane, often known as fluoroform ${\mathrm{CHF}}_3$, is classed as a polar molecule.
The bond angles between carbon, fluorine, and hydrogen in trifluoromethane (which has tetrahedral molecular geometry) are $109.5$degrees.

We have to identify that ${\mathrm{SO}}_3$molecule is polar or nonpolar.

Sulfur trioxide ${\mathrm{SO}}_3$ is a nonpolar molecule with three $\mathrm{S}-\mathrm{O}$ bonds and no lone pair of electrons in the central sulphur atom.
Because of its trigonal planar symmetrical structure, ${\mathrm{SO}}_3$ is also a nonpolar molecule.