Molten lithium nitrate-potassium nitrate eutectic: the reaction of chromium(II) chloride

Abstract

The strong reducing agent chromium(II) chloride reacted rapidly in molten lithium nitrate-potassium nitrate, at or above the melting point of the eutectic, initially forming a dark-brown-black solution [probably containing chromium(III) and chromium(VI)] and gaseous nitrogen dioxide, but at 200ºC giving a green precipitate (Cr₂O₃) and an orange solution of dichromate. Above 450ºC, a further slow reaction converted both compounds into a yellow solution of chromate(VI) containing nitrite partly formed by thermal decomposition of the nitrate.