Question

A conductivity cell has its electrodes 1 cm apart and each electrode has a cross section of 2 cm². When filled with `N/50` solution of an electrolyte MX, the cell shows a resistance of 166.5 ohms. Calculate the equivalent conductivity of MX at the given concentration.

Answer 1

Given:

Distance between electrodes l = 1 cm

Area of electrodes A = 2 cm²

Resistance R = 166.5 Ω

Concentration = `N/50` = 0.02 N

`"Cell constant" = l/A"`

= `1/2`

= 0.5 cm⁻¹

Specific Conductance `κ = "Cell constant"/R`

= `0.5/166.5`

= 0.0030045 Ω cm⁻¹

Equivalent conductance `Lambda_"eq" = (kappa xx 1000)/N`

= `(0.0030045 xx 1000)/0.02`

= `3.0045/0.02`

= 150.23 ohm cm² eq⁻¹