Question

Which of the following is NOT an example of an empirical formula?

• A. ${NO}_2$
• B. $N_2{O}_5$
• C. $N_2{O}_4$
• D. $N_2{O}_3$

Answer 1

Answer: (C)

$N_2{O}_4$

An empirical formula is the simplest whole-number ratio of all atoms in a molecule.

$i)N{O}_2\Rightarrow N:O=1:2\Rightarrow \text{Simplest - Empirical}$

$ii)N_2{O}_5\Rightarrow N:O=2:5\Rightarrow \text{Simplest - Empirical}$

$iii)N_2{O}_4\Rightarrow N:O=2:4\Rightarrow \text{Not Simple - Molecular}$

$iv)N_2{O}_3\Rightarrow N:O=2:3\Rightarrow \text{Simplest - Empirical}$

Hence, option $C$ is correct.