What is the difference between cathode, anode, and cation, and anion?

The basics of electrolysis along with the comparison of cationic vs anionic is explained in this article. Let us learn the basics of chemistry.

Introduction:

Electrolysis holds significant importance in all chemical studies and has various applications in the industrial process. This process is carried out in an electrolytic cell and it is used to bring chemical change in a solution when current is introduced in it. This chemical change is brought by the transfer of electrons in this solution.

During the process of electrolysis, an electron is lost or gained by the substance through a chemical transformation (a.k.a oxidation or reduction). This happens in between positive and negative electrodes in the electrolytic cell which are kept apart and dipped into a solution containing positively and negatively charged ions. The transformation needed for a substance can be on one of the electrodes, or mixed in solution.

What is anode and cathode?

The electrodes which we just explained in the above processes are classified as anodes and cathodes based on their polarity. Electrolysis involves the loss of electrons of a substance during an electrochemical reaction that happens at the anode (oxidation).

This electrode sucks electrons from the substance which is experiencing electrolysis, that is why it is denoted as a negative electrode or negatively charged electrode due to the entrance of electrons from this path back into the external circuit. This type of electrode is responsible for an increase in the oxidation state of the substance experiencing electrolysis.

On the other hand, the cathode is where a substance gains electrons coming from the external circuit (reduction). In other words, it provides electrons and this is denoted as a positively charged electrode in the electrolytic cell. This kind of activity happens during the deposition of metals from solutions, and the reduction of metal ions.

Both of them can be as classic electrodes or electrochemical half-cells, but both act as a connection of a solution to an external circuit and facilitate the oxidation half-reaction (represented on the reactant side of the chemical equation) and the reduction half-reaction (represented on the product side of the equation) in this solution. These two oppositely charged electrodes are also connected to the cationic vs anionic behavior of ions.

Comparison: Cationic and Anionic ions:

As mentioned above, the anode increases the oxidation state and the cathode does the opposite thus creating ions of the substance being held in the electrolytic cell. When this substance loses its electrons at the anode, it gets oxidized by becoming a positively charged ion (a cationic ion) termed a “cation”. This type of ion is positively charged which lost its electron to the anode. On the contrary, “anion” is negatively charged (hence an anionic ion) which gains electrons from the cathode.

The prime difference when considering cationic vs anionic is their polarity and the different electrodes at which they are being generated. Common examples of cationic ions are sodium (Na⁺), calcium (Ca²⁺), and iron (Fe³⁺) while sulfate (SO4²⁻), chloride (Cl⁻), and nitrate (NO3⁻) are common anionic ions.

Other differences in between the two are related to their applications and use in the industry. For example, cationic surfactants (e.g alkylammonium salts) are frequently used in the production of detergents, and hair conditioners) where they act as an agent to reduce surface tension and enhance the spreading of the product being applied. Other applications include use in water treatment (as polymers), as antiseptics (e.g. benzalkonium chloride), and in photographic development procedures (as dyes e.g. methylene blue).

On the other side, Anionic surfactants are frequently used in soaps, shampoos, and detergents to form micelles and emulsify oils and dirt. Here they are used as sodium dodecyl sulfate (SDS) and sodium lauryl sulfate (SLS). They are also often employed in textile Dyeing, water treatment, and in controlled drug delivery systems. Exchange resins of both anion and cations are used to remove desired (oppositely charged) substances from a solution undergoing electrolysis.  

Wrapping Up:

The comparison of cationic vs anionic explains the different polarities and locations of the ions that they generate during the electrolysis of a solution. Both have significant industrial applications in educational chemistry lab settings. The two electrodes that carry these different types of ions are connected to an external circuit where oxidation and reduction take place and give them different polarities, classifying them as cathode and anode.