The Oxidation of Free Methyl Radicals 15 pendence suggest that the charge of the product ion of equation 4 is more negative than -1. Since TaXeis stable over a considerably larger HF concentration range than NbXs~and since the high reactivity of the latter ion was attributed to one oxide ion in the complex,1 2 it appears that TaX3ĩ s not oxygenated. Thus in reaction (4) probably only chloride ions could be liberated. The HC1 dependence of is remarkably small and the sum of chloride and oxonium ions liberated is therefore probably not larger than one. Hence, since = 2, the most probable formula of the product tantalum complex becomes HTaX6F3-2 and equation ( 4) reduces to TaXEF-+ 2HF + H20 HTaXsFr! + H30+ (7)The corresponding molarity constants Kv> be-come 2.5 and 0.53 for 9 M HC1 and 3 M HC1, respectively.Summary 1. The anion exchange behavior of tantalum was studied for a number of HC1-HF mixtures. It was found to adsorb very strongly under most conditions, even in 9 M HC1.2. The species TaX6F~a nd HTaX6F3~2 have been tentatively identified and the molarity constants for the probable reaction TaX5F-+ 2HF + H20 ^Z±i HTaX6F3-2 + HsO + were estimated to be 2.5 and 0.53 for 9 M HC1 and 3 M HC1 solutions, respectively.Oak Ridge, Tennessee

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