Question

The molar conductivity for electrolytes A and B are plotted against C^1/2 as shown below. Electrolytes A and B respectively are :

• A.

  A	B
  Weak electrolyte	Weak electrolyte

• B.

  A	B
  Strong electrolyte	strong electrolyte

• C.

  A	B
  Weak electrolyte	strong electrolyte

• D.

  A	B
  Strong electrolyte	Weak electrolyte

Answer 1

The Correct Option is C

The question involves interpreting the graph of molar conductivity (\(Λ_m\)) versus the square root of concentration (\(C^{1/2}\)) for two electrolytes, A and B. To identify whether they are strong or weak electrolytes, we must understand their molar conductivity behavior:

1. Strong Electrolytes: These electrolytes dissociate completely in solution. Their molar conductivity tends to decrease slightly with an increase in concentration due to interionic interactions. The plot for strong electrolytes is typically a straight line or shows a very gentle slope as \(C^{1/2}\) increases.
2. Weak Electrolytes: These electrolytes do not dissociate completely. Their molar conductivity increases significantly with a decrease in concentration because more ions are formed as dilution shifts the equilibrium towards more dissociation. In the graph, weak electrolytes show a steep curve as \(C^{1/2}\) increases.

Based on the graph:

• Electrolyte A: The plot for A shows a sharp increase in molar conductivity as the concentration decreases. This behavior is typical for a weak electrolyte.
• Electrolyte B: The plot for B is almost flat, indicating that molar conductivity does not change much with concentration. This behavior is typical for a strong electrolyte.

Conclusion: Thus, electrolyte A is a weak electrolyte, and electrolyte B is a strong electrolyte. The correct answer is:

A	B
Weak electrolyte	Strong electrolyte

Answer 2

Explanation: The graph shows the variation of molar conductivity (\( \Lambda_m \)) with \( C^{1/2} \), the square root of concentration:

1. Electrolyte A: The molar conductivity of \( A \) increases steeply as \( C^{1/2} \) approaches 0, indicating \( A \) is a weak electrolyte. For weak electrolytes, the molar conductivity increases significantly with dilution due to ionization.
2. Electrolyte B: The molar conductivity of \( B \) remains relatively constant with \( C^{1/2} \), indicating \( B \) is a strong electrolyte. For strong electrolytes, the variation of molar conductivity with concentration is minimal.

Therefore:

Electrolyte A → Weak electrolyte, Electrolyte B → Strong electrolyte.

Final Answer is Option (3).