(2)Cl2； NaOHNaClO？
(3) Enriching bromine; Severe corrosion of equipment by strong acid?
(4) ; Severe corrosion of equipment by strong acid
(5)① condenser tube; ②Br 2 corrodes rubber; ③ Control the temperature of thermometer B and collect 59? Fraction at℃; 4 dark reddish brown; Liquid separation (or distillation)?