Question

Which of the following is not an organic compound?

• A. Hexane
• B. Urea
• C. Ammonia
• D. Ethyl alcohol

Answer 1

The correct option is C

Ammonia

Any chemical compound in which one or more carbon atoms are covalently connected to atoms of other elements, like hydrogen, oxygen, or nitrogen is called an organic compound.

The reaction of Nitrogen gas (${\mathrm{N}}_2$) and Hydrogen gas (${\mathrm{H}}_2$) at a certain temperature and pressure forms the Ammonia gas (${\mathrm{NH}}_3$).

The balanced reaction is written as:

${\mathrm{N}}_2\left(\mathrm{g}\right)+3{\mathrm{H}}_2\left(\mathrm{g}\right)\to 2{\mathrm{NH}}_3\left(\mathrm{g}\right)$

So, the Ammonia molecule does not contain carbon atoms and it is considered as an inorganic compound.

Urea is an organic fertilizer. It is prepared by the reaction liquid Ammonia (${\mathrm{NH}}_3$) and Carbon dioxide (${\mathrm{CO}}_2$).

The chemical formula of urea is Carbamide $\mathrm{Co}{\left({\mathrm{NH}}_2\right)}_2$. Urea does not contain carbon atoms.

Hexane ${\mathrm{C}}_6{\mathrm{H}}_{14}$ is an organic saturated hydrocarbon that contains six carbon atoms and fourteen hydrogen atoms..

Ethyl alcohol (${\mathrm{C}}_2{\mathrm{H}}_5\mathrm{OH}$) is also an organic compound that contains carbon atoms, oxygen atoms and hydrogen atoms..

Hence, option (C) is the correct option.