By diluting a weak electrolyte, specific conductivity `(K_(c))` and equivalent conductivity `(lambda_(c))` change as -

Options

A. both increase
B. `K_(c)` increases, `lambda_(c)` decreases
C. `K_(c)` decreases, `lambda_(c)` increases
D. Both decrease

Answer

To solve the question regarding the changes in specific conductivity (Kc) and equivalent conductivity (λc) upon diluting a weak electrolyte, we can follow these steps:

### Step 1: Understand the definitions
- **Specific Conductivity (Kc)**: It is the conductivity of a solution per unit concentration of the electrolyte.
- **Equivalent Conductivity (λc)**: It is defined as the conductivity of the solution divided by the normality of the solution.

### Step 2: Analyze the effect of dilution on a weak electrolyte
When a weak electrolyte is diluted:
- The volume of the solution increases.
- The concentration of the electrolyte decreases.

### Step 3: Effect on Equivalent Conductivity (λc)
- As the solution is diluted, the number of ions (current-carrying particles) per unit volume decreases, but the degree of ionization of a weak electrolyte increases with dilution.
- This results in an increase in the total number of ions available for conduction, leading to an increase in equivalent conductivity (λc).

### Step 4: Effect on Specific Conductivity (Kc)
- Although the number of ions increases due to higher ionization, the specific conductivity (Kc) is defined per unit volume.
- Since the volume increases significantly upon dilution, the specific conductivity (Kc) decreases as the concentration of ions per unit volume decreases.

### Step 5: Conclusion
From the analysis:
- **Equivalent Conductivity (λc)** increases with dilution.
- **Specific Conductivity (Kc)** decreases with dilution.

Thus, the final answer is that upon diluting a weak electrolyte, Kc decreases and λc increases.

### Summary of Changes:
- Kc: Decreases
- λc: Increases