LPガス炎照射による金ヒドロゾルの生成とその一,二の性状

Abstract

By applying the oxidizing flame of LP-gas to surfaces of the solutions of chlorauric acid of varing concentration that had been mixed with potassium hydroxide and held alkaline, we obtained violet-colored sols, and further, by keeping them on a bath of hot water for a while, we were capable of preparing red and stable sols, the conditions under which such might be formed being found as follows- composition of the reacting solution : ordinary distilled water 50ml, chlorauric acid solution (0.2%) 3-4ml and potassium hydroxide solution (0.1N) 1-2ml; flame application : 8-10min; water-bath treatment : 15-20min In passing, we have inferred the change in color from violet to red to be of chemical nature from a kinetical consideration, the activation energy found being 24 kcal/mol in the region of 50°-100℃. The coagulation values of some electrolytes were determined for a representative of the red sols; of the results, it should be worthy of notice that (1) the value of Hg (II)-ion is as small as about one tenth those of the other di-valent cations examined and (2) with several poly-valent cations such as Th (IV)-ion, there were observed irregular series in coagulation. Concerning the cause of sol formation due to the oxidizing flame, reducing action of nitrogen oxides generated might be considered as operative.