Question

Which of the following is a polar molecule?

• A. Ammonia $\left({\mathrm{NH}}_3\right)$
• B. Methane $\left({\mathrm{CH}}_4\right)$
• C. Ethylene $\left({\mathrm{C}}_2{\mathrm{H}}_4\right)$
• D. Carbon Tetrachloride $\left({\mathrm{CCl}}_4\right)$

Answer 1

The correct option is A

Ammonia $\left({\mathrm{NH}}_3\right)$

Explanation for correct option:

A. Ammonia $\left({\mathrm{NH}}_3\right)$

Polar molecule:

• In polar molecules there exist an electronegativity difference between the bonded atoms.
• Polar molecules have a net dipole moment.
• Examples of polar molecules are Ammonia as well as water.

Thus, Ammonia $\left({\mathrm{NH}}_3\right)$ is a polar molecule.

Explanation for incorrect options:

Non-polar molecule:

• In non-polar molecules, the electrons are shared equally.
• Non-polar bond exists between diatomic molecules or it exists in a symmetrical molecule.
• Non-polar molecules have zero dipole moment.
• Examples of non-polar molecules are Carbon tetrachloride as well as methane.

Methane$\left({\mathrm{CH}}_4\right)$, Ethylene$\left({\mathrm{C}}_2{\mathrm{H}}_4\right)$, and Carbon tetrachloride$\left({\mathrm{CCl}}_4\right)$ are Non-polar molecules. Thus all the other options B, C, and D stand incorrect.

Hence the correct option is A i.e. Ammonia $\left({\mathrm{NH}}_3\right)$.