Question

What are the empirical and molecular formulas of benzene?

Answer 1

Molecular formula:

• The molecular formula specifies the variety of types of atoms present in a chemical molecule.
• Benzene has molecular formula ${\mathrm{C}}_6{\mathrm{H}}_6$.

Empirical formula:

• An empirical formula is the shortest whole-number ratio of the various atoms in a molecule.
• Empirical formula of benzene is $\mathrm{CH}$

$$\begin{gathered} {\mathrm{C}}_6{\mathrm{H}}_6=6\mathrm{C}\mathrm{atoms}+6\mathrm{H}\mathrm{atoms} \\ \mathrm{Shortest}\mathrm{whole}\mathrm{no}.\mathrm{ratio}\mathrm{of}\mathrm{atoms}: \\ \mathrm{C}\mathrm{atoms}:\mathrm{H}\mathrm{atoms} \\ =6:6 \\ =1:1 \\ \mathrm{Hence}\mathrm{emperical}\mathrm{formula}=\mathrm{CH} \end{gathered}$$