Conductivity (unit Siemen’s S) is directly proportional to area of the vessel and the concentration of the solution in it and is inversely proportional to the length of the vessel then the unit of the constant of proportionality is

- S
^{2}m^{2}mol^{-2} - S
^{-2}m^{2}mol - S m mol
^{-1} - S m
^{2}mol^{-1}

**Answer**

S= (k*area*conc)/length

Solving for k and putting the units of other quantities, we get the unit of k as S mol-1 m2

**The correct option is D.**