Behaviour of some niobium(V), tantalum(V) and molybdenum(VI) compounds in disulphuric acid

Abstract

Pentaoxides and oxychlorides of niobium and tantalum and ammonium metaniobates and tantalates form H [NbO(HSO₄)₄] and H [TaO(HSO₄)₄] while pentahalides form H[M(HSO₄)₆] when dissolved in disulphuric acid. These acids behave as non-electrolytes in this solvent. At higher concentrations, there is indication of polymerization. Ammonium molybdate and molybdenum pentaoxide form MoO₂(HSO₄)₂ while molybdenum pentachloride forms H [Mo(HSO₄)₆] when dissolved in disulphuric acid.