Question

The equivalent conductances of two ions at infinite dilution in water at 25°C are given below: \[ \Lambda_0 (\text{Ba}^{2+}) = 127.00 \, \text{S cm}^2/\text{equiv}, \quad \Lambda_0 (\text{Cl}^-) = 76.00 \, \text{S cm}^2/\text{equiv} \] The equivalent conductance (in \( \text{S cm}^2/\text{equiv} \)) of BaCl\(_2\) at infinite dilution will be:

• A. 203
• B. 279
• C. 205.5
• D. 139.5

Hint:

The equivalent conductance of a salt is the sum of the conductances of its constituent ions.

Answer 1

The Correct Option is B

Step 1: Use the formula for equivalent conductance.
The total equivalent conductance at infinite dilution for a salt like BaCl\(_2\) is the sum of the equivalent conductances of its ions: \[ \Lambda_0 (\text{BaCl}_2) = \Lambda_0 (\text{Ba}^{2+}) + \Lambda_0 (\text{Cl}^-) \]
Step 2: Calculation.
Substitute the given values: \[ \Lambda_0 (\text{BaCl}_2) = 127.00 + 76.00 = 203.00 \, \text{S cm}^2/\text{equiv} \]
Final Answer: \[ \boxed{279} \]