The stability of tetravalent berkelium in acid solution and the absorption spectra of Bk(IV) and Bk(III)

Oxidation Potential of Bk(IV)-Bk(lll) System and Stability of Bk(IV) in Sulfuric Acid Solutions

“…3 presents absorption spectra of solutions of Bk in 1M H 2 S0 4 before (curve 1) and after (curve 2) oxidation. The spectrum of the oxidized Bk agrees with that reported in the work [10]. A strong absorption in λ < 250 nm range can be explained by the presence in the solution of a small amount of nitrate ions.…”

“…To characterize the rate of reduction, the authors of the papers often use the value ίιμ or the time during which the starting concentration Bk(IV) decreases by a half. In 1 M H 2 S0 4 , ΐ\μ equals, as reported by various authors, 0.83 h [5], 2.5 h [9], 4.1 h [10]. Other authors [10] have found that í ljí2 increases from 2.1 hto 16.7 h as the concentration of H 2 S0 4 solution rises from 0.05 M to 4.5 M. Our results show that a substantial part in the reduction of Bk(IV) belongs also to the reaction of the first order, which can be interpreted as a reduction of Bk(IV) by water.…”

“…In 1 M H 2 S0 4 , ΐ\μ equals, as reported by various authors, 0.83 h [5], 2.5 h [9], 4.1 h [10]. Other authors [10] have found that í ljí2 increases from 2.1 hto 16.7 h as the concentration of H 2 S0 4 solution rises from 0.05 M to 4.5 M. Our results show that a substantial part in the reduction of Bk(IV) belongs also to the reaction of the first order, which can be interpreted as a reduction of Bk(IV) by water. The values ίιμ , as Table 2 indicates, are practically constant in the range of 1 -6 M H 2 S0 4 and close to those already mentioned [9], This was also shown [6] for radiolytic reduction (2.2 h).…”

“…As reported by several authors [5,6,[9][10][11][12], in sulfuric, nitric, and phosphoric acid solutions, Bk(IV) is reduced to Bk(III) in a few hours: the cause underlying the reduction, as most of the authors see it, is the interaction with products of radiolysis of aqueous solutions. The reduction of Bk(IV) by water is also mentioned [6] as a factor.…”

“…The concentration of Bk in the working solutions was (4)(5)(6)(7)(8)(9)(10)(11)(12). IO" 5 M, and in a single experiment it has been used from 20 to 50 jug of 249 Bk.…”