Oxidation can be described as a reaction in which a molecule, atom, or ion loses its electrons, or its oxidation state is increased (gain of oxygen). Contrarily, reduction is an opposite reaction in which the oxidation state is decreased (loss of oxygen). While we can define the two reactions separately, these processes co-occur and this is why we call them oxidation-reduction or redox reactions. Although you might think that oxidation reactions are only used in labs, this is not true whatsoever. Rather, oxidation is involved in a variety of processes that we encounter on a daily basis. Here are ten reasons why oxidation is so important:
#1. Oxidation is involved in photosynthesis
During photosynthesis, plants use light energy, water, and carbon dioxide to create oxygen and chemical energy. Electron transfer occurs after the light is absorbed and this is when water molecules are oxidized to oxygen and carbon dioxide molecules are reduced to glucose. Without redox reactions, plants would not be able to produce oxygen or store the energy of sunlight in chloroplasts.
#2. Respiration is an oxidation reaction
As you may already know, plants produce their own food to live and this is done by cellular respiration. Respiration is the reverse of photosynthesis, during which glucose molecules are oxidized and oxygen molecules are reduced. Without the redox reactions occurring during respiration, our bodies would not be able to metabolize, generate energy, or discard waste products. Hence, cellular respiration is a vital process in living organisms.
#3. Combustion of substances is an oxidation reaction
The combustion or burning of any substance is an oxidation reaction. Typically, combustion reactions include oxygen that is reduced and the substance that is oxidized. For instance, various fuels are burnt to generate energy in numerous everyday and industrial activities. For example, if you own a car, oxidation occurs every time you drive. Besides, burning wood or coal for household purposes is also an example of combustion incorporating an oxidation reaction. Do you use natural gas or LPG for cooking? This is also a combustion reaction.
#4. Corrosion is an oxidation reaction
You have probably seen corroded metals, right? But did you know that certain materials deteriorate as a result of oxidation? Generally speaking, corrosion occurs when the atoms on the metal surface are oxidized. This happens because metals tend to easily lose electrons when exposed to a gas (e.g., air) containing oxygen. During the redox reaction, metals return to their natural oxidation states and oxygen is reduced, forming a metal oxide.
#5. Oxidation reactions can protect the surface of metals from corrosion
There are a couple of ways metal surfaces can be protected from corrosion, including coating the surface with paint/varnish or using non-corrosive metals. However, you can also prevent corrosion through the cathodic protection method. In this case, the metal of interest serves as a cathode (does not oxidize) and is connected to sacrificial anodes that undergo oxidation instead. As long as the sacrificial anodes are adequately monitored and regularly replaced, this method significantly increases the lifetime of metal objects.
#6. Oxidation is used for the treatment of agricultural and industrial wastewaters
There is no doubt that wastewater treatment and water purification protect humans and the overall ecosystem. Therefore, removing toxic chemicals from wastewater is key to avoiding severe health risks. There are several effective processes to treat wastewater and chemical water treatment is just one of them. Advanced oxidation processes (AOPs) involve the use of oxidizing agents (chlorine, ozone, calcium/sodium hypochlorite, etc.) that kill bacteria and remove organic or inorganic materials through reactions with hydroxyl radicals.
#7. The production of various chemicals is carried out through oxidation
Redox reactions are used for the synthesis of various chemicals. If you have ever written balanced chemical equations for your Chemistry homework, the majority of them could potentially involve oxidation and reduction. And this is exactly how compounds are produced in chemistry labs. In addition, electrolysis is yet another technique based on redox reactions that are responsible for the production of electrical current. Electrolysis is an effective technique for the production of metallic sodium, chlorine and fluorine gas, sodium hydroxide (caustic soda), molecular hydrogen and oxygen, and many more.
#8. Oxidation is key in organic synthesis
Oxidation reactions are of huge importance in organic synthesis. The main reason for this is that oxidation is a fundamental technique for creating new functional groups. For instance, primary alcohols can be oxidized to aldehydes and carboxylic acids, while the oxidation of secondary alcohols produces ketones. Moreover, as these functional groups are seen in various organic chemicals, oxidation is key to synthesizing new compounds or modifying already existing ones.
#9. Oxidation reactions are useful in quantitative analysis
Quantitative analysis is one of the essential aspects of analytical chemistry that allows scientists to determine the amount of chemical(s) in a sample. Redox titrations are among the most common methods used for the quantitative analysis of samples. This is a type of titration in which a redox reaction occurs between the analyte and titrant. The reactions between oxidizing and reducing agents enable chemists to quantitatively analyze substances. Such analyses are of fundamental importance in medical tests and for quality control.
#10. Oxidation is responsible for food spoilage
Last but not least, oxidation is one of the factors that facilitate food spoilage. When food is exposed to air, its chemical composition changes and the molecules start to break down. What really happens is that oxygen in the air has deteriorative effects on different food components, including fats, minerals, and vitamins. While oxygen causes the oxidation of these food components, it can also promote the growth of microorganisms or damage the food through enzymes.
