Nucleophilic And Electrophilic Substitution Reactions Both Aromatic And Aliphatic

In reaction (i), the reaction with NaI/acetone leads to a nucleophilic substitution of the bromine atom by the iodide ion, forming the product . In reaction (ii), a similar substitution occurs, but the iodide replaces the bromine atom, leading to the product .
Thus, the correct product from both reactions is an iodide substitution on the alkyl chain.