Question $1.(34$ pts$).$ Determine the oxidation states of each carbon present in the

following compounds: a$)$ iso$-$octane, b$)$ benzoic acid, c$)$ PCB $105,$ d$)$ dibutyl phthalate

and e$)$ phenanthrene $($Please draw the molecular structures and assign oxidation

states on the $C$ atoms$).$ Also comment on the possible transformation of these

compounds under oxidative and reductive conditions.