Question

What is the effect of decreasing concentration on the molar conductivity of a weak electrolyte

Answer 1

the number of ions per unit volume carrying the current decreases on dilution, so conductivity always decreases with decrease in concentration. However, molar conductivity increases with dilution.

Answer 2

Molar conductivity increases with a decrease in concentration for weak electrolytes.

• When the concentration of a weak electrolyte is low, the degree of ionization increases abruptly, and the ions in the solution rise sharply. Hence the molar conductivity of a weak electrolyte rises steeply at low concentrations.
• Dilution causes a rise in the number of ions and a fall in the number of ions per unit volume.
• Thus, as the concentration of a weak electrolyte decreases, its molar conductivity increases.