Which of the following given below can liberate B r 2 from KBr? F 2 , C l 2 , I 2 and C o n c . H 2 S O 4

Step-by-step solution

I 2 cannot liberate B r 2 from KBr, since I 2 is weaker oxidant than B r 2 . F 2 and C l 2 , being stronger oxidants than B r 2 , can liberate B r 2 from KBr. F 2 + 2 K B r → 2 K F + B r 2 C l 2 + 2 K B r → 2 K C l + B r 2 Reaction of conc. H 2 S O 4 with KBr forms HBr. HBr is a strong reducing agent so it reduces H 2 S O 4 to form a mixture of S O 2 and B r 2 . K B r + H 2 S O 4 → H B r + K H S O 4 K H S O 4 + K B r → H B r + K 2 S O 4 HBr so formed reduces H 2 S O 4 . H 2 S O 4 + 2 H B r → S O 2 + 2 H 2 O + B r 2