What is the Difference Between Equivalent Conductance and Molar Conductance?

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The main difference between equivalent conductance and molar conductance lies in the units of concentration they use. Here's a comparison of the two:

Equivalent Conductance:

  • Represents the conductance of a volume of solution containing one equivalent of an electrolyte.
  • The formula for equivalent conductivity is: λ = kV, where λ is the equivalent conductivity, k is the specific conductivity, and V is the volume in mL containing 1 g of electrolyte equivalent.
  • Uses the unit equivalent weight (equivalent per liter).
  • Focuses on the total charge on either anions or cations present in one formula unit of the electrolyte.

Molar Conductance:

  • Represents the conductance of a volume of solution containing one mole of electrolyte.
  • The formula for molar conductance is: Λ = kV, where Λ is the molar conductivity, k is the specific conductivity, and V is the volume in mL of the electrolyte having 1 g mole.
  • Uses the unit molarity (moles per liter).
  • Divides the conductance of an electrolyte by the number of moles of the electrolyte present in the solution.

In summary, equivalent conductance is related to the total charge of ions produced by one gram equivalent of an electrolyte, while molar conductance is related to the total conductance of ions produced by one mole of an electrolyte. The key difference lies in the units of concentration used, with equivalent conductance using equivalent weight and molar conductance using molarity.

Comparative Table: Equivalent Conductance vs Molar Conductance

Here is a table comparing equivalent conductance and molar conductance:

Property Equivalent Conductance Molar Conductance
Definition Equivalent conductance is the conductance of a volume of solution consisting of one equivalent of an electrolyte. Molar conductance is the conductance of all the ions furnished by one mole of an electrolyte present in a definite volume of the solution.
Unit Ohm^-1 cm^2 eq^(-1) Ohm^-1 cm^2 mol^(-1)
Basis Based on the number of gram equivalents of a substance. Based on the number of moles of a substance.
Calculation ∧e = K × V, where ∧e is equivalent conductance, K is specific conductance, and V is volume (in ml) of 1 gm-equivalent electrolyte. ∧m = ∧e × N, where ∧m is molar conductance, ∧e is equivalent conductance, and N is normality.
Factors Affecting Strong electrolytes fully ionize, resulting in the production of more ions and higher conductivities. Ionic size and mobility: An ion's mobility increases with its size while its conductivity decreases. Same as equivalent conductance.

Equivalent conductance and molar conductance are two types of conductivities that depend on the concentration of ions in a solution. The key difference between them is that equivalent conductance is based on the number of gram equivalents of a substance, while molar conductance is based on the number of moles of a substance.