Question

Which of the following electrolytic solutions of the same electrolyte has Maximum electrolytic conductivity at the same temp?

• A. 0.2 mole of solute is dissolved in 250 ml
• B. 0.3 mol in 600 ml
• C. 0.6 in 1000 ml
• D. 0.8 mole in 2000 ml

Hint:

While molar conductivity increases with dilution, specific conductivity ($\kappa$) increases with concentration.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Electrolytic conductivity (specific conductance, \(\kappa\)) is the conductance of a unit volume of solution.
Conductivity depends directly on the concentration of ions. As the concentration increases, the number of ions per unit volume increases, resulting in higher conductivity.
Step 2: Key Formula or Approach:
Calculate the molar concentration (Molarity, \(M\)) for each option:
\[ M = \frac{\text{moles of solute}}{\text{volume of solution in Liters}} \]
Step 3: Detailed Explanation:
Calculate concentrations for all cases:
(A) \(M = \frac{0.2}{0.250} = 0.8\text{ M}\)
(B) \(M = \frac{0.3}{0.600} = 0.5\text{ M}\)
(C) \(M = \frac{0.6}{1.000} = 0.6\text{ M}\)
(D) \(M = \frac{0.8}{2.000} = 0.4\text{ M}\)

Among the given options, option (A) has the highest concentration (\(0.8\text{ M}\)).
Since conductivity increases with the increase in concentration of the electrolyte (more ions per unit volume), solution (A) will have the maximum conductivity.
Step 4: Final Answer:
Solution (A) has the maximum concentration and thus the maximum electrolytic conductivity.