The SI unit of equivalent conductivity is **siemens meter squared per mole (S·m²/mol)**.
To understand this in more detail, let’s break down the concept:
1. **Equivalent Conductivity**: This is a measure of a solution's ability to conduct electricity. It is defined as the conductivity of a solution divided by the molar concentration of the electrolyte. Essentially, it gives an idea of how well ions in the solution can conduct electricity on a per-mole basis.
2. **Conductivity**: The basic unit of electrical conductivity is the siemens per meter (S/m). Conductivity is a measure of a material’s ability to conduct an electric current.
3. **Equivalent Conductivity Formula**:
\[
\text{Equivalent Conductivity} = \frac{\text{Conductivity (κ)}}{\text{Concentration (C)}}
\]
Where:
- **κ** is the conductivity of the solution.
- **C** is the concentration of the electrolyte in moles per liter (mol/L).
4. **Unit Derivation**:
- Conductivity has the unit siemens per meter (S/m).
- Concentration has the unit moles per liter (mol/L) or moles per cubic meter (mol/m³).
- When calculating equivalent conductivity, you divide conductivity (S/m) by concentration (mol/L), resulting in the unit S·m²/mol.
Thus, the SI unit for equivalent conductivity reflects how effectively a particular amount of electrolyte contributes to the overall conductivity of the solution.