what is equivalent conductivity
Equivalent conductivity is the conducting power of all the ions produced when one gram-equivalent of an electrolyte is dissolved in a solution, expressed as conductance per equivalent of electrolyte.
What Is Equivalent Conductivity?
In electrochemistry, equivalent conductivity (Λₑq) tells you how well one gram-equivalent of an electrolyte can conduct electricity in a given solution.
It is, in essence, the conductance of the volume of solution that contains exactly one gram-equivalent of the electrolyte between electrodes 1 cm apart with sufficiently large area.
Key Points (Quick Scoop Style)
- It is defined as the conducting power of all ions produced by one gram-equivalent of an electrolyte in solution.
- Symbol: Λₑq or Λ.
- Common unit: S cm² eq⁻¹ (Siemens cm² per equivalent).
- It depends on:
- Number of ions present (degree of dissociation).
* Mobility of ions in solution.
- It increases on dilution because ions are more free to move and more electrolyte becomes ionized, especially for weak electrolytes.
Important Formulas
- Definition-based relation
Λeq=K×V\Lambda_{eq}=K\times VΛeq=K×V
Where Λₑq is equivalent conductivity, K is specific conductivity (specific conductance), and V is the volume in cm³ containing one gram-equivalent of electrolyte.
- Relation with specific conductance and normality
Λeq=κ×1000N\Lambda_{eq}=\kappa \times \dfrac{1000}{N}Λeq=κ×N1000
Where κ is specific conductance (S cm⁻¹) and N is normality (eq L⁻¹).
These formulas show that equivalent conductivity scales with both the intrinsic conducting ability of the solution (κ) and how much volume is needed to hold one equivalent of solute.
Small Intuitive Picture
Imagine dissolving just enough salt (electrolyte) so that the amount corresponds to one gram-equivalent, then asking: “How strongly can the ions from exactly this amount of substance carry current in the solution?”
Equivalent conductivity is the numerical measure of that ability to conduct, normalized per equivalent, which makes it handy for comparing different electrolytes and different concentrations on the same basis.
TL;DR:
Equivalent conductivity is the conductance of the solution that contains one
gram-equivalent of electrolyte, usually expressed in S cm² eq⁻¹, and it
increases with dilution because ions move more freely and ionization improves.
Information gathered from public forums or data available on the internet and portrayed here.