What is the number of moles of ' C ' and ' H ' atoms respectively present in n mole molecule represented by…

The molecular structure of styrene consists of a benzene ring bonded to a vinyl group.

A benzene ring attached as a substituent contributes 6 carbon atoms and 5 hydrogen atoms, while the vinyl group $\mathrm{-CH=CH_2}$ contributes 2 carbon atoms and 3 hydrogen atoms.

Total carbon atoms: $6 + 2 = 8$

Total hydrogen atoms: $5 + 3 = 8$

The molecular formula is $\mathrm{C8H8}$.

For $n$ moles of styrene molecules, the number of moles of carbon atoms is $8 \times n = 8n$, and the number of moles of hydrogen atoms is $8 \times n = 8n$.

Final answer: $\boxed{\text{C}}$