Consider the following two reactions: (i) CH ₄ + Cl ₂ h A (major monochloro product) (ii) C ₆ H ₆ + 3 Cl ₂ h , 500 K B The types of reaction mechanisms involved in the formation of A and B, respectively, are :

Step-by-step solution

Reaction (i) is the halogenation of an alkane (methane) in the presence of sunlight or UV light ( h ). This proceeds via a free radical substitution mechanism to form chloromethane ( CH ₃ Cl ). Reaction (ii) is the reaction of benzene with chlorine in the presence of UV light at 500 K. Under these conditions, the stable aromatic ring undergoes a free radical addition reaction to form benzene hexachloride ( C ₆ H ₆ Cl ₆ ), completely saturating the ring. Therefore, the mechanisms are free radical substitution and fr