The given reaction illustrates the direct iodination of ethylbenzene. Unlike chlorination or bromination, this reaction is reversible due to the formation of a strong reducing byproduct. To drive the equilibrium in the forward direction, Reagent Z is required. Identify the most suitable Reagent Z from the following.

Step-by-step solution

Direct iodination of aromatic compounds is a reversible process because the byproduct, HI , is a strong reducing agent. It reduces the formed iodoarene back to the starting arene. Ar-H + I₂ Ar-I + HI To drive the equilibrium in the forward direction, the HI produced must be consumed. This is achieved by carrying out the reaction in the presence of an oxidizing agent such as HIO₃ , HIO₄ , or HNO₃ . The oxidizing agent oxidizes HI to I₂ , thereby preventing the reverse reaction and shifting the equilibrium to the rig