Question

The molar conductivity of 0.02 M electrolytic solution is \(220\ \Omega ^{-1}\text{ cm}^{2}\text{ mol}^{-1}\) at \(25\ ^{\circ }\text{C}\). Find its conductivity.

• A. \(0.0044\ \Omega ^{-1}\text{ cm}^{-1}\)
• B. \(0.0022\ \Omega ^{-1}\text{ cm}^{-1}\)
• C. \(0.0011\ \Omega ^{-1}\text{ cm}^{-1}\)
• D. \(0.0033\ \Omega ^{-1}\text{ cm}^{-1}\)

Hint:

Use molar conductivity = conductivity x 1000 / molarity.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept
Molar conductivity is \(\Lambda_m=\dfrac{\kappa\times1000}{M}\), where \(\kappa\) is the conductivity in \(\Omega^{-1}\text{cm}^{-1}\) and \(M\) is molarity.

Step 2: Rearrange
\(\kappa=\dfrac{\Lambda_m\times M}{1000}\).

Step 3: Calculation
\(\kappa=\dfrac{220\times0.02}{1000}=0.0044\ \Omega^{-1}\text{cm}^{-1}\).

Final Answer:
The conductivity is \(0.0044\ \Omega^{-1}\text{cm}^{-1}\). \[ \boxed{\text{(A) }0.0044\ \Omega ^{-1}\text{ cm}^{-1}} \]