What is conductivity

The resistance of an electrolyte solution between two flat or cylindrical electrodes separated by a given distance is used to determine its electrical conductivity. Water electrolysis is usually avoided by using an alternating voltage. A conductivity metre is used to determine the resistance. The most common frequencies utilised are 1–3 kHz. The Debye–Falkenhagen effect is a phenomenon that occurs when the frequency dependence is minor but becomes noticeable at extremely high frequencies.

What is conductivity?

Now we will learn about what we mean by conductivity, thermal conductivity and lastly what is molar conductivity.

Conductivity-

The ease with which an electric charge or heat may travel through a substance is measured by conductivity. A conductor is a substance that allows an electric current or heat energy to pass with minimum resistance. Metals, semiconductors, and insulators are the three types of materials. Metals are the most conductive materials, whereas insulators (ceramics, wood, and plastics) are the least, the type of the electrolyte that has been added

The polymer type, solvent utilised, and availability of ionizable salts all have a role in solution conductivity. Increases in solution conductivity lead to a considerable reduction in fibre diameters, while poor solution conductivity leads to inadequate electrically induced jet elongation. However, in the presence of large electric fields, high solution conductivity is exceedingly unstable, resulting in severe bending instability and a wide diameter dispersion. As a result, appropriate solution conductivity is critical for fibre creation during the electrospinning process.

Solvation determine the conductivity of electrolytic (ionic) solutions-

1.The size of the ions generated.

2.The viscosity and composition of the solvent.

3.The electrolyte’s concentration.

4.Thermometer (it increases with the increase of temperature).

S.I unit- Siemens per metre (S/m)

Thermal conductivity-

Thermal energy (most often referred to as heat) may pass through a substance. Metals, for example, enable heat to pass through them very fast. Imagine touching a piece of metal with one hand and a piece of wood with the other. Metal of the two materials would be colder, you would be able to feel the coldness, however, they are at the same temperature. This is what is known as relative thermal conductivity.

Metal has a better heat transferability, or thermal conductivity, than wood, which allows the heat from your hand to escape more quickly. Wrapping anything with material that does not have a high heat transferability or thermal conductivity, such as an insulator, is the greatest way to keep something cool. Ceramics and polymers are often excellent insulators, however keep in mind that polymers have a low melting temperature. That implies that depending on the melting temperature of the polymer, it may melt if you build anything that will become really hot.

It may alternatively be described as the amount of heat that can be carried through a plate of unit thickness of a certain material, with the faces of the plate varied by one unit of temperature, per unit time per unit area.

Thermal conductivity is achieved by molecular agitation and contact rather than bulk movement of the material. Heat flows down a temperature gradient from a high-temperature, high-molecular-energy region to a lower-temperature, lower-molecular-energy region. This transfer will continue until the temperature reaches thermal equilibrium. The pace at which heat is transmitted is determined by the size of the temperature gradient as well as the material’s unique thermal properties.

Thermal conductivity is the reciprocal of thermal resistivity, which evaluates an object’s capacity to resist heat transmission, and is measured in W/m•K (Watts per metre per degree Kelvin) in the International Systems of Units (SI unit).

k= Q∗L/A(T2−T1)

Where-
Q – Heat flowing (W)
L – Length or thickness of the material (mm)
A – Surface area m2
(T2−T1)- Gradient of temperature(K)

Molar conductivity-

Molar conductance refers to the conductivity of a single mole of an electrolyte solution. It is symbolised by the symbol Λ 

The conductance of a volume of a solution containing one mole of a dissolved component is defined as the molar conductivity Λm of an electrolyte.

Connection to Conductivity- The conductivity of a 1 mL solution is its conductance (k)

1 mL electrolyte conductance =k

100 mL electrolyte conductance = 1000 k

Λm =1000×k/M

S.I unit- S⋅m2⋅mol-1

Conclusion-

In this article we read about conductivity, its types- molar and thermal. The conductivity of water may be used as a broad indicator of its quality. Each water body has a somewhat stable conductivity range that may be used as a baseline for comparison with regular conductivity measurements once established. The conductivity of water increases with the concentration of ions in it. We indirectly estimate the amounts of dissolved salts, bases, and acids when we evaluate the conductivity of a water sample.