Question

What is the chemical formula of ammonia?

• A. ${\mathrm{NH}}_2$
• B. $\mathrm{NH}$
• C. ${\mathrm{N}}_2\mathrm{H}$
• D. ${\mathrm{NH}}_3$

Answer 1

The correct option is D

${\mathrm{NH}}_3$

The explanation for the correct option -

• Ammonia is the compound of Nitrogen.
• It is made up of Nitrogen and Hydrogen.
• The valency of Nitrogen and Hydrogen is $+3\mathrm{and}-1$.
• By the criss-cross method, $$\begin{gathered} \mathrm{N}\mathrm{H} \\ +3-1 \\ \overline{{\mathrm{NH}}_3} \end{gathered}$$
• Hence, the molecular formula of ammonia is ${\mathrm{NH}}_3$

The explanation for the incorrect options -

• Option A, B, and C are incorrect because ${\mathrm{NH}}_2,\mathrm{NH},\mathrm{and}{\mathrm{N}}_2\mathrm{H}$ does not fulfil the valency of Nitrogen and Hydrogen.

Hence, Option D is the correct answer.