(i)Cynohydrin will be formed in this reaction by following mechanism.
(ii) Dialkyl cadmium when treated with acid chloride will replace the alkyl group with chloride group to form a ketone. Since dialkyl cadmium is less reactive than Grignard's reagent, it will not further react with ketone. (C6H5CH2)2Cd+2CH3COCl→2C6H5CH2COCH+CdCl2
(iii) The carboxylic acid present in reactant has α hydrogen, which when treated with redP/Br2 will undergo Hell-Volhard-Zelinsky reaction to replace the α hydrogen with a Halogen.