Question 4 (10 points) Which of the following is the strongest activating group in electrophilic aromatic substitution reactions? Save 1) -CH₂CHS 2) -OCH 3) -NO₂ 4) -N(CH3)2 Question 5 (10 points) Which of the following species is attacked by benzene in the electrophilic nitration reaction? 1) HNO3 2) NO₂ Save 3) NO₂ 4) NO Question 6 (10 points) Which of the following compounds undergoes reaction with HNO/H2SO4 at the fastest rate? 1) ethylbenzene 2) nitrobenzene 3) chlorobenzene 4) acetophenone