Cruywagen J J, van de Water R F
Department of Chemistry, University of Stellenbosch, Republic of South Africa.
Talanta. 1993 Jul;40(7):1091-5. doi: 10.1016/0039-9140(93)80171-m.
The hydrolysis of lead(II) has been investigated by potentiometric titrations (ionic medium 1.0M NaClO(4) and 1.0M KNO(3)) and enthalpimetric titrations (ionic medium 1.0M NaClO(4)) at 25 degrees . The reaction model that gave the best fit to the data for 1.0M NaClO(4) comprised the following five ions: Pb(OH)(+), Pb(3)(OH)(2+)(4), Pb(3)(OH)(+)(5), Pb(4)(OH)(4+)(4) and Pb(6)(OH)(4+)(8). The formation constants, and enthalpy changes (kJ/mol) for these species, defined according to equation (1), have the values log beta(11) = -7.8, DeltaH(0)(11) = 24; log beta(34) = -22.69, DeltaH(0)(34) = 112; log beta(35) = -30.8, DeltaH(0)(35) = 146; log beta(44) = -19.58, DeltaH(0)(44) = 86; log beta(68) = -42.43, DeltaH(0)(68) = 215. Equilibrium constants determined in nitrate medium show good agreement with those pertaining to perchlorate medium if complexation of lead(II) with nitrate is taken into account.
通过电位滴定法（离子介质为1.0M高氯酸钠和1.0M硝酸钾）以及在25摄氏度下的热焓滴定法（离子介质为1.0M高氯酸钠）对铅（II）的水解进行了研究。对于1.0M高氯酸钠，与数据拟合最佳的反应模型包含以下五种离子：Pb(OH)(+)、Pb(3)(OH)(2+)(4)、Pb(3)(OH)(+)(5)、Pb(4)(OH)(4+)(4)和Pb(6)(OH)(4+)(8)。根据方程（1）定义的这些物种的生成常数和焓变（kJ/mol）的值为：logβ(11)= -7.8，ΔH(0)(11)= 24；logβ(34)= -22.69，ΔH(0)(34)= 112；logβ(35)= -30.8，ΔH(0)(35)= 146；logβ(44)= -19.58，ΔH(0)(44)= 86；logβ(68)= -42.43，ΔH(0)(68)= 215。如果考虑铅（II）与硝酸根的络合作用，在硝酸盐介质中测定的平衡常数与高氯酸盐介质中的平衡常数显示出良好的一致性。
