The Molar conductivity of 0.05 M solution of MgCl ₂ is 194.5 ~ohm ⁻¹ ~cm ^2 per mole at room temperature. A Conductivity cell with electrodes having 3.0 ~cm ^2 surface area and 1.0 ~cm apart is filled with the solution of MgCl ₂ . What would be the resistance offered by the conductivity cell?

Step-by-step solution

The molar conductivity _m is related to the conductivity and molarity C by the formula _m = 1000 C . Given _m = 194.5 ohm ⁻¹ cm ^2 mol ⁻¹ and C = 0.05 M , we calculate the conductivity as follows: = _m C 1000 = 194.5 0.05 1000 = 9.725 1000 = 0.009725 S cm ⁻¹ . The cell constant G^ * is defined as l A , where l is the distance between electrodes and A is the surface area of the electrodes. G^ * = 1.0 cm 3.0 cm ^2 = 0.3333 cm ⁻¹ . The relationship between conductivity , resistance R , and cell constant G^ * is = G^ *