The incorrect statement(s) among (a) – (c) is (are) :(a) W(VI) is more stable than Cr(VI). (b) in the presence of HCl, permanganate titrations provide satisfactory results. (c) some lanthanoid oxides can be used as phosphors.11

a) W(VI) is more stable than  is correct as going down the  group, stability of higher oxidation state increases in case of d-block elements.b) is wrong as permanganate can oxidise HClc) is correct as some lanthanoid oxides are used as phosphors