Oxygen is the vital gas responsible for life on earth.
It is the most common gas available in the air.
It accounts for 20.8% of all gases in the air.
It is chemically represented as “O” and element oxygen is represented as O2.
It is one of the widely distributed gases in the atmosphere after Nitrogen.
It is a diatomic molecule with an atomic number of 8 and the molecular weight of 16.
As plain molecule oxygen is stable but tends to react. But in its atomic form, it is highly reactive.
It is a life-sustaining element for all the living beings. On the contrary, it can destroy many substances when exposed to it.
Uses of oxygen are as follows:
- For Energy in the body.
- Provides food
- In toxicity treatment.
- In health care
- For combustion of fuels in automobiles.
- For analysis of substances.
- For sterilization.
- For chemical reactions.
- For sanitation.
- For Welding
For Energy supply: We all live in an oxygen-rich atmosphere. It is a life-generating gas and it is carried in space and also in deep sea diving. All the living animals and also plants take up oxygen for production of required energy.
Oxygen in humans and animals is carried by the hemoglobin in blood from the air in the lungs. It is then carried to deeper most parts of the body tissues and distributed to all the cells. This oxygen at cellular level is taken up by mitochondria where it is used to break down the glucose molecule into energy (ATP; adenosine tri-phosphate) and water molecule and carbon-dioxide. This carbon-dioxide is released out of the body again by expiration through lungs.
Animals living in water also take up oxygen. Hence, the air-water combination is critical even in aquariums as the fishes need to take oxygen from water through gills.
Thus oxygen supports the generation of energy required for the sustenance of life on earth.
For food formation:
From above picture we can notice that oxygen is used in reversible reaction. Wherein, in right hand side it is made due to formation of food. While in the left hand side it is way used up to generate energy by respiration. This process of oxygen release happens in plants. They are autotrophs and make up their own food by use of sunlight and carbon-dioxide. The plants release oxygen into the air due to photosynthesis. This oxygen release is formed due to combination of carbon-dioxide and water molecules. Here oxygen element play a key role in formation of carbohydrate in presence of sunlight due to its high electro-negative property. If not for oxygen element, no other elements can replace its role.
In toxicity and poisoning: In case of poisoning by cyanide, oxygen can help buy time to detoxify the cyanide from the system. Cyanide binds to mitochondrial complexes and arrests energy generation leading to immediate death. Oxygen when given in high doses can minimize this cyanide induced arrest of energy generation. Thus it can save life and pave way for further detoxification of cyanide by sodium thio sulphate.
In health care: When there is a respiratory insufficiency in diseases like COPD (chronic obstructive pulmonary disorder, pneumonia, heart failure then oxygen therapy is used to aid breathing.
Even in case of poisoning, oxygen therapy may be given to stabilize the patient. Thus medical oxygen is an essential aid in critical condition to save life and buy time for further procedures.
For combustion of fuels in automobiles: We all have studied the requirement of air or oxygen to support fire. Oxygen is necessary to burn the fuels in the automobiles. So there are separate air filters which take air into the combustion chamber of automobiles. Here oxygen reacts with fuels to generate energy required to run the automobiles. Without oxygen it would be difficult to burn the fuels. Hence we use carbon-dioxide to put of flames in times of fire at home offices or in buildings.
For analysis of substances: Sample analysis is a key aspect of quality control in industry. It is also used in research. Of the available analytical methods in chemistry, flame photometry and atomic absorption spectrometry use flame to determine the elements in the sample. For this oxygen is needed to generate flame of high temperature so as to convert excite electrons in the atoms. So, oxygen is used as one of the combination gases in the above methods of analysis.
For sterilization: Oxygen being an electro negative element is a strong sterilizing agent. It can destroy microbes in a given environment be it water or land. It is used in the form of hydrogen peroxide H2O2 as a disinfectant to kill microbes on surgical equipment.
Also, there is a method called oxygen plasma treatment where by oxygen molecule is broken down to release single oxygen atom or its ions which are deadly toxic. They are used for sterilization of substances at room temperatures.
For chemical reactions: Oxygen is a part of many chemical reactions. An essential chemical reaction is an oxidation-reduction reaction. This reaction is one where there is addition or removal of oxygen. The addition is termed as oxidation while removal of oxygen is termed as reduction. Besides oxygen, hydrogen and electrons are also involved in the process. These chemical reactions are used for synthesis, analysis, titration and also for degradation purposes.
For sanitation: Oxygen is also used for sanitation. The sanitation is measured in terms of BOD and COD. BOD means biological oxygen demand and COD means chemical oxygen demand. When we take them in detail, BOD is the amount of dissolved oxygen required by bacteria or other microbes to destroy the waste.
Sometimes this oxygen consumption can be severe leading oxygen depletion and death of aquatic animals.
COD means the amount of chemical needed to destroy a certain amount of waste. In both, the processes oxygen is involved in destroying the waste. Read more details on biological oxygen demand.
Even we can notice metals like iron destroyed by oxidation when exposed to air for a long time. This is called rust, but actually it is oxidation of the metal due to oxygen in the air. Hence oxygen is a potent agent which can destroy substances. Though in our terms this destruction by rust formation is disadvantageous, it is the law of nature to derange substances. So oxygen supports this nature law by destroying them.
In Gad welding: Oxygen is used in gas welding instead of regular air. Use of oxygen is said to increase the flame temperature at thereby help in localized melting of metal at the point of exposure.
a) Propane: Air flame has a temperature of 1,980 °C
b) propane: oxygen flame has a temperature of 2,253 °C
So oxygen is not only used as a breathing gas but also as an important chemical tool.