Molar conductivity (∧)

The electrolytic conductivity is not suitable for comparing conductivities of different solutions: the conductivity of a solution depends on the number of ions present in unit volume of the solution, so a solution of higher concentration contains more ions and exhibits a higher conductivity than a solution of lower concentration. To compare the conductivities of different solutions meaningfully, they must have the same concentration.

In 1880 the German physicist F.W.G. Kohlrausch introduced the term molar conductivity, denoted by $\Lambda$ (lambda — the book prints it as the wedge symbol ∧). The molar conductivity of an electrolytic solution is the electrolytic conductivity $k$ divided by its molar concentration $c$:

SI units of $k$ are $\mathrm{S\,m^{-1}}$ and those of $c$ are $\mathrm{mol\,m^{-3}}$; hence the SI units of $\Lambda$ are $\mathrm{S\,m^2\,mol^{-1}}$. The common units employed for molar conductivity are $\mathrm{\Omega^{-1}\,cm^2\,mol^{-1}}$.

Significance of molar conductivity : To understand the significance of $\Lambda$, consider the volume of a solution containing 1 mole of dissolved electrolyte. Suppose this solution is placed between two parallel electrodes 1 cm apart and large enough to accommodate it. The electrical conductance exhibited by this solution is the molar conductivity — the electrical conductance generated by all the ions obtained from 1 mole of the electrolyte. …