Question

A cell, with cell constant $0.4c{m}^{-1}$, has the resistance of $40ohm$ of a $0.01M$ solution of an electrolyte, then the molar conductivity in $oh{m}^{-1}c{m}^{2}mo{l}^{-1}$ will be

• A. $10^4$
• B. $10^3$
• C. $10^2$
• D. $1$

Answer 1

Answer: (B)

Cell constant $=0.4c{m}^{-1}$ Resistance $=40ohm$
$\therefore$ Conductivity $=\frac{1}{40}oh{m}^{-1}$
Concentration of solution $=0.01M$
Specific conductivity $=$ conductivity $\times$ cell Constant
$=\frac{1}{40}oh{m}^{-1}\times 0.4c{m}^{-1}$
$\therefore$ Specific conductivity $=0.01oh{m}^{-1}c{m}^{-1}$
Molar conductivity $=\frac{\text{ specific conductivity }\times 1000}{\text{ concentration }(\text{ molarity })}$
$=\frac{0.01\times 1000}{0.01}oh{m}^{-1}c{m}^{2}mo{l}^{-1}$
$\therefore$ Molar conductivity $=1000oh{m}^{-1}c{m}^{2}mo{l}^{-1}$