Question

The specific conductances in $oh{m}^{-1}c{m}^{-1}$ of four electrolytes P, Q, R and S are given below:
$P\Rightarrow 5.0\times {10}^{-5}$
$Q\Rightarrow 7.0\times {10}^{-8}$
$R\Rightarrow 1.0\times {10}^{-10}$
$S\Rightarrow 9.2\times {10}^3$

Which of the electrolyte will offers highest resitance to the passage of electric current?

• A. P
• B. Q
• C. S
• D. R

Answer 1

The correct option is D R

We know,
$G=\kappa \times \frac{A}{l}$
Where,
$G$ is conductance
$\kappa$ is conductivity
$\kappa =G\times \frac{l}{A}$

$\kappa =\frac{1}{R}\times \frac{l}{A}$

$\kappa \propto \frac{1}{R}$


$\frac{l}{a}$ is the cell constant $\left(G^{\ast }\right)$ of the cell.

i.e., more is the resistance, less is the specific conductance
Hence, $R(1.0\times {10}^{-10})$ has the highest resistance.