A conductivity cell reads 74.0 Ω when it is filled with 0.100 mol/L potassium chloride…

The cell constant is $G^* = \dfrac{l}{A}$, in $\text{m}^{-1}$. The conductivity is $\kappa = \dfrac{G^*}{R}$, in $\text{S/m}$, and $1\ \text{S/cm} = 100\ \text{S/m}$. A cell is calibrated with potassium chloride: $G^* = \kappa R$. A solution of $0.100\ \text{mol/L}$ potassium chloride has $\kappa = 1.29\ \text{S/m}$ at $298\ \text{K}$.