Question

Specific conductance of \( 0.1 \, \text{M} \, \text{HNO}_3 \) is \( 6.3 \times 10^{-2} \, \text{ohm}^{-1} \, \text{cm}^{-1} \). The molar conductance of the solution is:

• A. \( 100 \, \text{ohm}^{-1} \, \text{cm}^2 \, \text{mol}^{-1} \)
• B. \( 515 \, \text{ohm}^{-1} \, \text{cm}^2 \, \text{mol}^{-1} \)
• C. \( 630 \, \text{ohm}^{-1} \, \text{cm}^2 \, \text{mol}^{-1} \)
• D. \( 6300 \, \text{ohm}^{-1} \, \text{cm}^2 \, \text{mol}^{-1} \)

Hint:

Molar conductance is proportional to specific conductance and inversely proportional to the concentration of the solution.

Answer 1

The Correct Option is C

The formula for molar conductance is: \[ \Lambda_m = \kappa \cdot \frac{1000}{C}, \] where: - \( \kappa = 6.3 \times 10^{-2} \, \text{ohm}^{-1} \, \text{cm}^{-1} \), - \( C = 0.1 \, \text{M} \). Now, substituting the given values: \[ \Lambda_m = 6.3 \times 10^{-2} \cdot \frac{1000}{0.1} = 6.3 \times 10^2 = 630 \, \text{ohm}^{-1} \, \text{cm}^2 \, \text{mol}^{-1}. \] Final Answer: \[ \boxed{630 \, \text{ohm}^{-1} \, \text{cm}^2 \, \text{mol}^{-1}}. \]