Question

The equivalent conductance of a $0.2\, N$ solution of an electrolyte was found to be $200\,\Omega ^{-1} cm ^{2} eq ^{-1}$. The cell constant of the cell is $2\, cm ^{-1}$. The resistance of the solution is

• A. $50\,\Omega $
• B. $400\,\Omega $
• C. $100\,\Omega $
• D. None of these

Answer 1

Answer: (A)

$\Lambda_{v}=200\, \Omega^{-1} cm ^{2} eq ^{-1}$
$C _{ N }=0.2\, N , cm ^{-1}$
$K=\frac{\Lambda_{v} \times C_{N}}{1000}=\frac{200 \times 0.2}{1000 \times 10}=\frac{1}{25} \Omega^{-1} cm ^{-1}$
$R=\frac{1}{K} \cdot \frac{l}{a}=25 \times 2=50\, \Omega .$