Question

Define the following and write the formula and unit of each:
(i) Specific conductivity, (ii) Molar conductivity.

Answer 1

(i) Specific conductivity: The specific conductivity of a solution at a given dilution is the conductance of $one$ $cm$ cube of the solution. It is represented by $\kappa$ (kappa).
Formula:
$\kappa =\frac{1}{\rho }=\frac{1}{A}\times \frac{1}{R}$
Where,
$\rho =$ specific resistance
$l=$ length
$A=$ Area
$R=$ Resistance
Unit: ${Ohm}^{-1}{cm}^{-1}$
(ii) Molar conductivity: At definite temperature the conductivity of ions in a solution containing $one$ $gm$ mole of electrolyte is called molar conductivity. It is denoted by $\mu$ or ${\Lambda }_m$
Formula: ${\Lambda }_m=\kappa \times V$
${\Lambda }_m=\kappa \times \frac{1000}{m}$
where,
${\Lambda }_m=$ molar conductivity
$\kappa =$ specific conductivity
$m=$ molarity
$V=$ volume $=V{cm}^3$
Unit: ${Ohm}^{-1}{cm}^2{mol}^{-1}$