Kohlrausch's law of independent migration of ions states that:

Kohlrausch's law: at infinite dilution, where ions are far enough apart that interionic forces vanish, each ion contributes a characteristic conductivity independent of its counter-ion. So $\Lambda^\circ_m(\text{A}_x\text{B}_y) = x\,\lambda^\circ_{\text{A}^{y+}} + y\,\lambda^\circ_{\text{B}^{x-}}$. This is the basis for finding $\Lambda^\circ_m$ of weak electrolytes from the values for strong electrolyte combinations.