In lithium nitrate-potassium nitrate eutectic, nickel(II) chloride was found to undergo a Lux-Flood acid-base reaction from 320 degrees C with a maximum rate at 450 degrees C. Nickel(II) oxide was the solid product and gaseous nitrogen dioxide and oxygen were evolved. The reaction of chromium(III) chloride in this melt was more complex, the initial reaction from 160 degrees C forming chromium(III) oxide, together with nitrogen dioxide and oxygen, followed at higher temperatures by further reactions to form dichromate at 405 degrees C, and then partially to form chromate from 490 degrees C. The impurity nitrite, present at equilibrium concentration from the thermal decomposition reaction, is considered to be important in determining the reaction temperatures and products, particularly of these latter reactions.