Consider the following list of reagents, acidified K₂Cr₂O₇, alkaline KMnO₄, CuSO₄, H₂O₂, Cl₂, O₃, FeCl₃, HNO₃ and Na₂S₂O₃. The total number of reagents that can oxidise aqueous iodide to iodine is

The total number(s) of stable conformers with non-zero dipole moment for the following compound is(are)

Among PbS, CuS, HgS, MnS, Ag₂S, NiS, CoS, Bi₂S₃ and SnS₂ the total number of black coloured sulphides is

Consider all possible isomeric ketones including stereoisomers of MW = 100. All these isomers are independently reacted with NaBH₄ (Note : stereoisomers are also reacted separately). The total number of ketones that give a racemic product(s) is/are