Equivalent Conductivity

• The conductivity of a volume of solution containing one equivalent of an electrolyte is called equivalent conductivity. It is represented by the symbol Λ.

• Consider the volume of a single electrolyte equivalent in a V cm3 solution. Its conductance is comparable to that of comparable conductance. 

• A 1 cm3 electrolyte solution’s conductance is defined as the specific conductance. (A distance of 1 cm separates two electrodes with a cross-sectional size of 1 cm2). In this part, we will talk about similar conductivity in great detail.

• It’s defined as the total conducting power of all the ions generated when one gram of an electrolyte is dissolved in a solution.

• It’s expressed as and is linked to specific conductance, with the M representing the molarity of the solution and the C representing the concentration in gram equivalents per litre (or Normality). The word above is often used, and molar conductance always manages to take its place.

Conductance measurement by experiment

C ∝ R

Since the conductance(C)of a solution is reciprocal of its resistance(R), determining its conductance experimentally entails measuring its resistance.

K =1/p 

Where p is resistivity =R(a/l)

We’ve seen that conductivity (k) is the reciprocal of resistivity, where G is the equivalent conductance unit of the cell and l is the distance between two electrodes with the same cross-section area.

Electricity conductivity (k)

Equivalent Conductivity is the conductance, also known as the conducting power of all different ions in a solution, produced after dissolving one gram equivalent of the electrolyte in the solution. It can be said that the conductance in the electrolytic solution is mainly dependent on the ions’ concentration present in the solution. Therefore, it is great to achieve comparable results for several different electrolytes. It is denoted by ∧. 

The formula of Equivalent Conductivity

The Equivalent conductance that is λ = k × V

Units of Λ  is m2ohm-1 equiv-1 or m2 Siemens equiv-1

Factors Influencing Electrolyte Conductance

An electrolyte is a substance that dissociates in solution to produce ions and, thus, conducts electricity when dissolved or molten. The conductance of electricity by ions in solutions is electrolytic or ionic conductance. 

Electrolyte

The electricity conductance by ions in solutions is electrolytic or ionic conductance. The following factors govern the flow of electricity through an electrolyte solution. 

• Nature of electrolytes or interionic attractions: The lower the solute-solute interactions, the greater the freedom of ion movement and the higher the conductance.

• Ion solvation: The greater the magnitude of solute-solvent interactions, the greater the extent of solvation and lower the electrical conductance.

• The solvent’s composition and viscosity: The greater the solvent-solvent interactions, the greater the viscosity, and greater the resistance offered by the solvent to ion flow, and lower the electrical conductance.

• Temperature: As the electrolytic solution’s temperature rises, solute-solvent and solvent-solvent interactions weaken, increasing electrolytic conductance.

Conductors and insulators

Conductors are materials that enable electrons to flow freely from one component to the other without resistance. Electric fields in the form of electrons are present in conductors, allowing the electrons to flow freely.

In contrast, insulators prevent electrons from flowing through one element to the other. As a result, any charge that passes through insulators stays only at the juncture where the materials meet, rather than spreading across the entire material.

Calculation of conductance

We’ve already concluded that the conductance of the solution is inversely proportional to its resistance. Consequently, the resistivity of the pure solvent can be used to calculate conductance:

Because k conductivity is the reciprocal of p resistivity, we can say:

 k = 1/p

p = R(a/l)

k = 1/R(l/a)

 k = G(l/a) 

Where G represents cell conductance; l represents the distance between two electrodes with a cm2 as the cross-section area, and l/a represents the cell constant, represented by cm-1.

The conductance can be calculated as follows after determining the cell constant and solution conductance:

k = G x cell constant

Alternatively, conductivity equals conductance multiplied by the cell constant.

The following factors influence electrolytic or ionic conductivity:

• The properties of the electrolyte present in the solution

• The ions are produced during the process size and solvation capacity.

• The properties of the solvent, such as its resistance to changing shape or mobility (viscosity).

• The electrolyte concentration in the solution

• The temperature at which the solution is put together

Equivalent conductance at infinite dilution :

As a solution dilutes, ionises, or the number of ions increases, the value of equivalent conductance also increases.

Conclusion 

Thermal conduction is determined not only by the nature of the material but also by the geometry of the conducting element. For example, the conductance of copper wires of varying lengths and/or sections will vary. Therefore, conductivity is defined to compare the contribution of materials to thermal conductivity while trying to isolate it from contour effects.

To conclude, conductivity increases with a cross-section (as more flow can pass through simultaneously) and decreases with duration for a linear electric flow across a conducting element (as more resistance is found).