The variation in `Lambda_m` with concentration for a strong electrolyte can be represented by the equation, `Lambda_m=Lambda_m^@ -AC^(1//2)` The value of constant A for a given solvent and temperature depends upon the type of electrolyte i.e., cations and anions produced on dissociation of electrolyte in the solution .
Which of the following statements is correct regarding variations of molar conductivity with concentration.

Options

A. Molar conductivity decrease with decrease in concentration
B. Variation in molar conductivity of weak and strong electrolytes is same.
C. Molar conductivity increases with decrease in concentration.
D. When concentration of the solution approaches zero, the molar conductivity is known as conductance.

Answer

To solve the question regarding the variation of molar conductivity (\( \Lambda_m \)) with concentration for a strong electrolyte, we will analyze the given equation and derive the implications step by step.

### Step 1: Understanding the Equation
The equation given is:
\[ \Lambda_m = \Lambda_m^0 - A C^{1/2} \]
Where:
- \( \Lambda_m \) is the molar conductivity at a certain concentration.
- \( \Lambda_m^0 \) is the molar conductivity at infinite dilution.
- \( A \) is a constant that depends on the type of electrolyte and the solvent.
- \( C \) is the concentration of the electrolyte.

### Step 2: Analyzing the Terms
From the equation, we can see that:
- As the concentration \( C \) increases, the term \( A C^{1/2} \) also increases because \( A \) is a positive constant and \( C^{1/2} \) increases with increasing \( C \).
- Since \( \Lambda_m^0 \) is a constant, the equation shows that \( \Lambda_m \) decreases as \( C \) increases.

### Step 3: Conclusion on Molar Conductivity
From the analysis, we conclude:
- When the concentration of the electrolyte increases, the molar conductivity \( \Lambda_m \) decreases.
- Conversely, this means that molar conductivity increases when the concentration decreases.

### Step 4: Selecting the Correct Statement
Given the analysis, the correct statement regarding the variation of molar conductivity with concentration is:
- Molar conductivity increases with a decrease in concentration.

### Final Answer
Thus, the correct option is:
- **Molar conductivity increases with decrease in concentration.**

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