Resistance of a conductvity cell filled with a solution of an electrolyte of concentration 0.1 M is 100 `Omega`. The conductivity of this solution is 1.29 `Sm^(-1)`. Resistance of the same cell when filled with 0.02M of the same solution is `520 Omega`. the molar conductivity of 0.02M solution of the electrolyte will be:

Options

A. `124xx10^(-4) S m^(2) mol^(-1)`
B. `1240xx10^(-4) S m^(2) mol^(-1)`
C. `1.24xx10^(-4) S m^(2) mol^(-1)`
D. `12.4xx10^(-4) S m^(2) mol^(-1)`

Answer

A

Explanation

`kappa=1/Rxxl/A`
`1.29=1/100xxl/A`
`l/A=129 m^(-1)`
`Lambda_(m)=kappaxx1000/M`
`=(1/Rxxl/A)xx1000/M`
`=(1/520xx129)xx1000/0.02xx10^(-6)`
`=124xx10^(-4) S m^(2) mol^(-1)`