硫氰酸钨(V)络合物稳定常数的测定

DETERMINATION THE STABILITY CONSTANT OF TUNGSTEN(V) -POTASSIUM THIOCYANATE COMPLEX

测定了水溶液中硫氰酸钨(Ⅴ)络合物的吸收光谱,最大吸收波长为405 nm.在盐酸浓度为3.56 mol/L、离子强度为0.088 mol/L的溶液中,硫氰酸钾溶液浓度在0.018～0.088 mol/L范围内,与硫氰酸钨(Ⅴ)络合物的平均摩尔吸光系数△-ε呈函数关系.测得络合物的络合比为1:4.计算出络合物的各级累积稳定常数和摩尔吸光系数分别为:β1=40.73,β2=1.10×103,β3=2.40×104,β4=4.16×105,Δε1=9.33×103,Δε2=9.64×103,Δε3=9.93×103,Δε4=1.10×104(t=17.7℃).

The absorption spectra of tungsten(V)-thiocyanate was determined in the water solution, in which λmax was 405 nm. In the solution condition of [H+] =3.56 mol/L and I=0.088 mol/L ,△εis a function of [KSCN] when [KSCN] is 0.018-0.088 mol/L. The complex ometric proportion determined is 1:4. The stability constants determined are β1 =40. 73 ,β2= 1. 10×103, β3=2. 40×104 ,β4=4. 16×105 respectively and the molar extinction coefficients are △δ1=9. 33×103, △δ2=9. 64×103, △δ3= 9. 93×103,△δ4= 1. 10×104(t=17.7℃) respectively.