Question

Which of the following molecules is non-polar in nature?

• A. $POCl _{3}$
• B. $CH _{2} O$
• C. $SbCl _{5}$
• D. $NO _{2}$

Answer 1

The Correct Option is C

To determine which of the given molecules is non-polar, we need to consider both molecular geometry and the electronegativities of the constituent atoms. A molecule is generally non-polar if it has a symmetrical shape such that the dipole moments of all bonds cancel each other out.

1. Analyzing $POCl_{3}$:

   The molecule $POCl_{3}$ (Phosphoryl Chloride) is tetrahedral in geometry. Phosphorus is the central atom, bonded to one Oxygen and three Chlorine atoms. Due to the different electronegativities of Oxygen and Chlorine, the dipole moments do not cancel out, making $POCl_{3}$ polar.

2. Analyzing $CH_{2}O$:

   Formaldehyde ($CH_{2}O$) has a trigonal planar geometry. The Oxygen atom is more electronegative than Carbon, thus creating a net dipole moment towards the Oxygen. This makes $CH_{2}O$ a polar molecule.

3. Analyzing $SbCl_{5}$:

   Antimony pentachloride ($SbCl_{5}$) has a trigonal bipyramidal structure. The symmetry of this shape allows the dipole moments from the bonds to cancel each other out, making $SbCl_{5}$ non-polar.

4. Analyzing $NO_{2}$:

   Nitrogen dioxide ($NO_{2}$) is an angular / bent molecule because of the lone electrons on nitrogen. This shape causes an uneven distribution of electron density, resulting in a polar molecule.

Therefore, among the given options, the non-polar molecule is $SbCl_{5}$ due to its symmetrical geometry.