MOLTEN LITHIUM NITRATE-POTASSIUM NITRATE EUTECTIC - SOME REACTIONS OF COPPER(II) AND OF METALLIC SILVER

Copper(II) nitrate trihydrate has been successfully dehydrated in lithium nitrate-potassium nitrate eutectic at 140°C. At 300°C it commenced reaction as a Lux-Flood acid precipitating copper(II) oxide. With potassium iodide it reacted at 140°C to form copper(I) iodide and iodine but at 180°C the insoluble product was a mixture of copper(I) iodide and copper(II) oxide. With powdered silver a violent reaction occurred at 160°C, yielding silver(I) cations, nitrogen dioxide and copper(II) oxide. The stoichiometries of these reactions have been established and some reaction pathways suggested. Metallic silver was found to react to a much larger extent with a Lux-Flood acid (pyrosulphate) in solution than with nitrogen dioxide giving support to the nitryl cation as the acidic species in nitrate melts. © 1979.