Question

By diluting a weak electrolyte, specific conductivity $\left(K_c\right)$ and equivalent conductivity $\left({\lambda }_c\right)$ changes as:

• A. Both increase
• B. $K_c$ increases, ${\lambda }_c$ decreases
• C. $K_c$ decreases, ${\lambda }_c$ increases
• D. Both decreases

Answer 1

Answer: (C)

$K_c$ decreases, ${\lambda }_c$ increases

When the solution of weak electrolyte is diluted, the volume of the solution increases, hence equivalent conductivity $\left({\lambda }_c\right)$ increases. However, during this process, the number of current carrying particles per ${cm}^3$ decreases, hence specific conductivity $\left(K_C\right)$ decreases.

[Note: ${\lambda }_c=\frac{1000\times K_c}{Normality}$]