Question

The resistance of a conductivity cell with cell constant $1.14c{m}^{-1}$ , containing 0.001 $M$ $KCl$ at 298 $K$ is 1500 $\Omega$ . The molar conductivity of 0.001 $MKCl$ solution at 298 $K$ in $S$ $c{m}^{2}mo{l}^{-1}$ is _______. (Integer answer)

• A. 760
• B. 760.00
• C. 760.0

Answer 1

Answer: (A), (B), (C)

Cell constant $=\frac{l}{a}=1.14c{m}^{-1}$

$\text{Concentration,}c=0.001M$
$\text{Temperature,}T=298K$
$\text{Resistance,}R=1500\Omega$

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

$\kappa =\frac{1}{R}\left(\frac{1}{a}\right)=\frac{1}{1500}\times 1.14Sc{m}^{-1}$

$\text{Molar conductance,}{\Lambda }_m=\frac{k\left(Sc{m}^{-1}\right)\times 1000\left(c{m}^3{L}^{-1}\right)}{c\left(mol{L}^{-1}\right)}$

$=\frac{\frac{1}{1500}\times 1.14\times 1000}{0.001}$

$=760Sc{m}^{2}mo{l}^{-1}$