A conductivity cells has been calibrated with a 0.01 M 1:1 electrolyte solution (specific conductance,) `K= (1.25 xx 10^(-3) S cm^(-1))` in the cell and the measured resistance was 800 ohms at `25^(@)C`. The cell constant will be

Options

A. `1.02 cm^(-1)`
B. `0.102 cm^(-1)`
C. `1.00 cm^(-1)`
D. `0.5 cm^(-1)`

Answer

C

Explanation

`K= 1.25 xx 10^(-3) S cm^(-1) : rho = 1/K = (1)/(1.25 xx 10^(-3))`
`R = rho (1)/(A), therefore 800= (1)/(1.25 xx 10^(-3)) xx (l/A)`,
Where `l/A =` Cell constant