邻硝基苯甲酸合镧配合物稳定常数的测定

Determinion of stability constants of lanthanum(Ⅲ) complex with o-nitro-benzoic acid

采用 pH电位法 ,在一定量、一定浓度的硝酸镧和邻硝基苯甲酸 (以HL表示 )的混合溶液中 ,用一定浓度的氢氧化钾溶液进行滴定 ,根据消耗氢氧化钾溶液的量、体系的 pH值及一系列的关系式 ,作出了La(Ⅲ ) L体系的生成曲线 ,用半整数法得出了LaL3 (邻硝基苯甲酸合镧 )配合物的逐级稳定常数和累积稳定常数 :β1=1.7× 10 3 ,β2 =6 .0 3× 10 6,β3 =5 .13× 10 10 .

The stability constants of complex of lanthanum (Ⅲ) with o-nitro-benzoic acid was determined by potentiometric titration at 20.00 ℃.The mixed solution of La(NO-3)-3 and o-nitro-benzoic aid (indicated as HL) was titrated by KOH solution. The results indicated that the stability constants of complex of lanthanum (Ⅲ) with o-nitro-benzoic acid are β-1=1.70×10+3,β-2=6.03×10+6,β-3={5.13×10+{10}}.