Question

Which of the following electrolytic solutions of the same electrolyte has maximum electrolytic conductivity at the same temperature?

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

Hint:

Conductivity increases with concentration because the number of ions available to carry electric current increases.

Answer 1

The Correct Option is A

Concept: Electrolytic conductivity (\(\kappa\)) depends on the number of ions present per unit volume of solution. Greater concentration means greater conductivity.

Step 1: Calculating molarity of each solution.
\[ M = \frac{\text{moles}}{\text{volume in liters}} \]
• Solution (1): \[ \frac{0.2}{0.250} = 0.8\,M \]
• Solution (2): \[ \frac{0.3}{0.600} = 0.5\,M \]
• Solution (3): \[ \frac{0.6}{1.000} = 0.6\,M \]
• Solution (4): \[ \frac{0.8}{2.000} = 0.4\,M \]

Step 2: Comparing concentrations.
\[ 0.8M > 0.6M > 0.5M > 0.4M \] Hence, solution (1) has maximum concentration.

Step 3: Relating concentration to conductivity.
Higher concentration means more ions per unit volume, hence higher conductivity.