2 3 4 4' 5-pentachlorobiphenyl July 8, 2019 16 32 64 128 2 3′ 4 4′ 5-pentachlorophenol 2 2' 4 5 5'-pentachlorobiphenyl 2 4 5-trichlorophenol Which of the following is 2-chloro-4-ethylphenol
