Question

Which of the following statement is true regarding Molar conductivity?
1. Molar conductivity decrease with decrease in concentration
2. Molar conductivity increases with a increase in concentration
3. Molar conductivity increases with a decrease in concentration
4. No relation between Molar conductivity and concentration

Answer 1

Correct Answer - Option 3 : Molar conductivity increases with a decrease in concentration

The correct answer Molar conductivity increases with a decrease in concentration.

• Molar conductivity:
  • It is the conductance of volume V of a solution containing 1 mole of the electrolyte kept between two electrodes with the area of cross-section A and distance of unit length. 
  • Molar conductivity has the SI unit S m² mol⁻¹.
  • Molar conductivity increases with a decrease in concentration.
  • This is because the total volume V of the solution containing one mole of the electrolyte increases on dilution.

      Λ_m= k*V

• Λm - Molar conductivity
• V - Volume 
• k - Specific conductance

Notes:

Specific conductance - The conductivity of a solution is defined as the conductance of a solution of 1 cm in length and area of crosssection 1 sq. cm. Specific conductance is the inverse of resistivity.

      k = 1/p 

• p - Resistivity