Question

Define molar conductivity. How is it related with conductivity?

Answer 1

Hint – Both the terms molar conductivity and conductivity are different. Molar conductivity is the conductivity of one molar electrolytic solution placed between two electrodes which are one centimetre apart and have enough area of cross section to hold the entire volume.

Complete step-by-step answer:

Molar conductivity of an electrolytic solution can be defined as the conductance of volume V of an electrolytic solution containing one mole of electrolyte and kept between two electrodes between two electrodes with an area of cross-section A and distance of unit length.

Molar conductivity is denoted by symbol ${\Lambda _m}$ and it is given by the formula-
${\Lambda _m} = \dfrac{K}{c}$
Here, c = concentration in moles per volume
K = Specific Conductivity/ Conductivity
${\Lambda _m}$ = Molar Conductivity

Now, in the above formula K is the specific conductivity/ conductivity which can be defined as the conductivity of an electrolyte solution at any given concentration of unit volume of solution kept between two platinum electrodes with a unity area of cross-section and at a unit distance.
The molar conductivity is related to conductivity as- ${\Lambda _m} = \dfrac{K}{c}$.

Note – Whenever such types of questions appear, then as mentioned in the solution first we have explained everything about the molar conductivity and then describing the conductivity. And hence showing the relation between the two by the formula, ${\Lambda _m} = \dfrac{K}{c}$ .