Answer
a. acetylene, $C_2H_2$, and benzene $C_6H_6$
c. nitrogen dioxide, $NO_2$, and dinitrogen tetroxide, $N_2O_4$
Work Step by Step
a. Both $C_2H_2$ and $C_6H_6$ have the empirical formula of $CH$.
c. Both $NO_2$ and $N_2O_4$ have the empricial formula $NO_2$.
