含义Meaning
强电解质的摩尔电导率随 √c 线性下降，外推到零得极限摩尔电导率；无限稀释时各离子独立迁移，Λ°为阴阳离子极限摩尔电导之和（1875–1900）。由此可求弱电解质的 Λ°。
Strong-electrolyte molar conductivity falls linearly with √c, extrapolating to Λ°; at infinite dilution ions migrate independently, so Λ° is the sum of ionic contributions (1875–1900) — which gives Λ° for weak electrolytes too.
符号说明Symbols
| 符号Symbol | 含义 Meaning | 单位 Unit |
|---|---|---|
| \(\Lambda_m^\circ\) | 极限摩尔电导率limiting molar conductivity | S·m²·mol⁻¹ |
| \(\lambda^\circ\) | 离子极限摩尔电导率（H⁺ 349.8，OH⁻ 198.6，K⁺ 73.5，Cl⁻ 76.3 S·cm²/mol）limiting ionic conductivities (H⁺ 349.8, OH⁻ 198.6, K⁺ 73.5, Cl⁻ 76.3 S cm² mol⁻¹) | S·m²·mol⁻¹ |
推导Derivation
科尔劳施由实验发现 √c 关系；德拜–休克尔–昂萨格理论解释：离子氛产生弛豫效应和电泳效应，减速与 √I 成正比。
Kohlrausch found the √c law; Debye–Hückel–Onsager theory explains it via relaxation and electrophoretic effects ∝ √I.
无限稀释时离子间无作用，各自贡献可加。
At infinite dilution contributions add.
弱电解质：\(\Lambda^\circ(\mathrm{HAc}) = \Lambda^\circ(\mathrm{HCl}) + \Lambda^\circ(\mathrm{NaAc}) - \Lambda^\circ(\mathrm{NaCl})\)。
For weak electrolytes combine strong-electrolyte values.
适用条件与局限Assumptions & limitations
√c 律只在很稀（< 约 0.001 mol/L）时准确；弱电解质不能直接外推。
The √c law holds only below ~10⁻³ M; weak electrolytes cannot be extrapolated.
例题Worked example
H⁺ 和 OH⁻ 的离子电导特别大，因为它们通过格罗特斯链式机理在氢键网络中“接力”传递。
H⁺ and OH⁻ conduct exceptionally well by the Grotthuss mechanism.