Specific and Molar Conductivity Variation of Conductivity with Concentration

In electrochemistry, specific conductivity, also known as conductivity of an electrolytic solution at a specific concentration, refers to the conductance produced by a unit volume of solution held between two platinum electrodes with a unit cross-section and separated by a unit length. Because the amount of ions per unit volume that carry the current in a solution falls with dilution, the conductivity of a solution decreases with dilution. Conductivity is defined as the ability of a solution to conduct current. It is represented by the Greek letter kappa (k). This is the symbol for the conductivity unit, which is denoted by the following letter:

k = siemens x meters-1

Some of The Variables That Have An Impact On Conductivity Are As Follows

It is a highly sensitive physical quantity that can be significantly affected by a multitude of factors…. Among these factors are the ones listed below.

• The chemical composition of an electrolyte
• Molecular mass is measured in millimetres for ions.
• The concentration of the solution’s concentration in terms of strength.
• Temperature
• The chemical composition of the solvent

Molar Conductivity

The molar conductivity of a substance is a measure of how well it transmits electrical current or water.

The conductance of volume V of a solution containing one mole of electrolyte held between two electrodes with an area of cross-section A and a distance of unit length is defined as the conductance of volume V of a solution containing one mole of electrolyte at a specific concentration.

Molar conductivity = ⋀m = k/cWhere,

⋀m = molar conductivity 

c =  Specific conductivity

C = concentration in moles per volume

Molar conductivity is calculated using the equation below:

⋀m (S cm2 mol-1) = k(S/cm)×1000/molarity(mol/L)

What Is the Difference Between Strong Electrolytes and Weak Electrolytes?

As soon as the solid crystalline salts are submerged in a solvent, they begin to dissociate into the paired charged particles. This was discovered in the year 1884 by a scientist by the name of Svante Arrhenius. In recognition of this achievement, he was awarded the Nobel Prize in the year 1903. Michael Faraday used the term “ions” to refer to the salts that dissociate in a solution and form charged particles as a result. According to Faraday, the process of electrolysis results in the production of ions. Arrhenius, on the other hand, discovered that salts contain ions even in the absence of an electric current, and that chemical reactions occur as a result of interactions occurring between the ions.

When strong and weak electrolytes react together, they do not entirely dissociate into the solvent, whereas weak electrolytes can totally dissolve in aqueous solution. Molecular constituents of the solution, as well as the ions present in the electrolyte, are present. Weak electrolytes only partially ionizes in water, whereas strong electrolytes entirely ionise in water. Weak electrolytes are defined as bases and acids that are too weak to dissolve in water. Strong electrolytes are those that contain strong bases, strong acids, and strong salts. Salt is regarded a strong electrolyte despite the fact that it has a poor solubility in water. This is due to the fact that whatever amount of salt dissolves in water is totally ionised.

Examples of weak electrolytes include: Acetic acid (CH3COOH) is a type of organic acid. Acetic acid is the acid present in vinegar, and it is a weak acid. It is an electrolyte that is particularly soluble in water and is used as a diuretic. However, when it is dissolved in water, the majority of its original molecule remains in its original shape rather than being transformed into an ion. Ethanoate is the name given to this primordial form. The acetic acid is dissolved in water and ionises to form ethanoate and the hydronium ion, which are both toxic. As a result, acetic acid is considered a weak electrolyte.

Conclusion

As a result of their propensity to conduct electricity, the presence of free ions in electrolytes causes the electrolytes to conduct electricity. It is analogous to the way that free electrons enhance the conduction of electricity in metallic conductors, which is comparable in both cases. It is the Arrhenius equation or principle that is used to define electrolytic conduction when it comes to electrical current.

We’re all familiar with electrolytic solutions, which are made by dissolving a variety of salts in a solution and allowing the solution to evaporate. It is not necessary for the salts to be ionic all of the time in order to function properly. The only requirement is that the compound be formed of ions that have diametrically opposite charges to one another.

The Arrhenius principle asserts that when an electrolyte is dissolved in water, the electrolyte molecules will be split into two unique charged ions, each with a different charge.

The charged particles in the solution have complete freedom to move about in their environment. It is possible for positive ions, also known as cations, to migrate towards a negative electrode, also known as a cathode, in order to reduce the charge on their own surface. During the process of oxidation, positive ions will gravitate toward the positive electrode or anode while simultaneously oxidising themselves. The passage of charged particles across a fluid medium is what causes electric conduction to take place.