Question

Which from following is the correct relationship between molar conductivity (\(\Lambda\)), conductivity (\(\text{k}\)) and molarity (\(\text{M}\)) of solution for electrolyte?

• A. \(\text{k} = \frac{\Lambda \times \text{C}}{1000}\)
• B. \(\Lambda = \frac{100 \times \text{k}}{\text{C}}\)
• C. \(\Lambda = \frac{\text{k} \times \text{C}}{1000}\)
• D. \(\text{k} = \frac{1000 \times \text{C}}{\Lambda}\)

Hint:

Always remember: \(\Lambda = \frac{1000k}{C}\). Rearranging gives all required relations.

Answer 1

The Correct Option is A

Concept:
Molar conductivity \((\Lambda)\) is defined as the conductivity of a solution containing one mole of electrolyte placed between electrodes 1 cm apart. Mathematically: \[ \Lambda = \frac{\text{k} \times 1000}{C} \] where:

• \(\text{k}\) = conductivity
• \(C\) = molarity (mol L\(^{-1}\))

Step 1: Start from the standard formula. \[ \Lambda = \frac{1000 \text{k}}{C} \]
Step 2: Rearrange to find conductivity. Multiplying both sides by \(C\) and dividing by 1000: \[ \text{k} = \frac{\Lambda \times C}{1000} \]
Step 3: Match with options. This matches option (A).
Step 4: Conclusion. \[ {\text{k} = \frac{\Lambda \times C}{1000}} \]