Question

Select the correct statement(s) for the weak electrolyte.

• A. They have higher degree of dissociation at higher concentration
• B. The change in ${\Lambda }_m$ with dilution is due to decrease in the degree of dissociation and number of ions in the solution that contain electrolyte
• C. ${\Lambda }_m$ increases steeply on dilution near high concentration
• D. At infinite dilution, electrolyte dissociate completely but at such low concentration the conductivity of solution is low and cannot be measured accurately.

Answer 1

Answer: (D)

Weak electrolytes have lower degree of dissociation at higher concentrations. Change in ${\Lambda }_m$ with dilution is due to increase in the degree of dissociation and consequently the number of ions in total volume of solution that contain $1$ mole of electrolyte. ${\Lambda }_m$ increases steeply on dilution, specially near lower concentrations.
At infinite dilution electrolyte dissociate completely but at such low concentration the conductivity of the solution is so low that it cannot be measured accurately.