Resistance of a conductivity cell filled with a solution of an electrolyte of concentration 0.1M is 100ohm. The conductivity of this solution is `1.29 S m^(-1)`. Resistance of the same cell when filled with 0.2M of the same solution is 520ohm. The molar conductivity of 0.02M solution of the electrolyte will be

Options

A. `124 xx 10^(-4) S m^(2) mol^(-1)`
B. `1240 xx 10^(-4) S m^(2) mol^(-1)`
C. `1.24 xx 10^(-4) S m^(2) mol^(-1)`
D. `12.4 xx 10^(-4) S m^(2) mol^(-1)`

Answer

A

Explanation

`k= (1)/(R ) xx (l)/(A), 1.29 = (10/(100) xx(l)/(A), (l)/(A)= 129 m^(-1)`
`Lamda_(m) = k xx (1000)/(M) = ((1)/(R )xx (l)/(A)) xx (1000)/(M) = ((1)/(520) xx 129) xx (1000)/(0.02) xx 10^(-6)= 124 xx 10^(-4) Sm^(2) mol^(-1)`