Question

Define limiting molar conductivity.

Answer 1

Limiting molar conductivity is the molar conductivity at infinite dilution or approximately zero concentration of the electrolyte. For a strong electrolyte the limiting molar conductivity can be determined by extrapolating the molar conductivity v/s concentration curve and it is less than unity. While for a weak electrolyte it cannot be determined by extrapolating the curve.

According to Kohlrausch, ${\Lambda }_m={\Lambda }_m^0-K\sqrt{c}$

where, ${\Lambda }_m=$ molar conductivity

${\Lambda }_m^0=$ molar conductivity at infinite dilution

$K=$ Kohlrausch coefficient

$c=$ concentration