Introduction
Oxygen is an element with an atomic number 8. It has 8 electrons, protons & electrons. It is one of the crucial elements on earth.
History of oxygen
The history of oxygen starts with Leonardo da Vinci. In the past, the air was believed to be an elemental substance. Now we know that it is not. Air is composed of a number of different elemental gasses.
The famous Italian artist, scientist, and inventor, Leonardo da Vinci (1452 - 1519) goes on record as the first to suggest responsibly that air is composed of at least two different gasses. Furthermore, he found that one of the gasses supported both flame and life: "Where flame cannot live animal that draw breath can live."
Oxidation
Between 1630 and 1756, chemists repeatedly demonstrated that metals that normally gained weight when heated in the atmosphere did not gain weight when heated in the absence of air. Today we know that metal oxidizes when heated in air and that the oxides of metal are heavier than the metal itself. Oxygen is one of the most abundant elements in the cosmos.
Although Carl Wilhelm Scheele and Joseph Priestly share the honors for being the first to isolate oxygen, Antoine Lavoisier was the one who recognized oxygen as a true element and gave oxygen its present name.
Oxygen production
Small amounts of oxygen can be generated in the laboratory by heating potassium chlorate (KCl03) with a manganese dioxide (Mn02) catalyst. Potassium chlorate is "anxious" to give up its oxygen atoms to form potassium chloride (KCl) and oxygen.
Heating alone does not release the oxygen very effectively nor does mixing the potassium chlorate with manganese dioxide. If you heat a mixture of the two chemicals, however, you get plenty of free oxygen. The manganese dioxide, in this case, is not consumed by the reaction. It is a true catalyst, and this particular reaction is a classic in elementary chemistry classes because it clearly demonstrates a catalytic reaction.
Electrolysis of water
Small amounts of oxygen can also be obtained by electrolyzing water. Strictly speaking, electrolyze a mixture of water (not just water) and a good electrolyte such as sodium sulfate (Na2S04), or Glauber's salt. The sodium sulfate does not participate directly in the reaction, so the scheme will not produce sodium, sodium hydroxide, nor any sulfates. Rather, the sodium sulfate (or similar salt) improves performance by neutralizing the ionic charges throughout the bath.
Oxygen is produced on a commercial scale by the fractional distillation of liquid air. The critical temperature of oxygen is - 118°C. Since liquid air is held at about 198°C, fractional distillation produces nitrogen (N2) first at -147°C, followed by argon (Ar), and oxygen.
Commercial production of Oxygen in Steel Industry
Most commercially produced oxygen is consumed by the steel industry. Pure oxygen is blown over the molten steel where it converts excess carbon to carbon dioxide gas and oxidizes other impurities so they can later be removed with the slag.
Importance of Oxygen
Oxygen is very important. Oxygen is absolutely vital for sustaining life as we know it. The oxygen atom is one of the most abundant atomic species in the cosmos. Oxygen is the most common element in the earth's crust. Diatomic oxygen gas comprises more than 20% of the atmosphere.
Uses of Oxygen
The most important use of oxygen comes to all of us is the air we breathe. Commercially speaking, the United States annually produces some 15 million tons of liquid oxygen for applications in industry, aerospace, the military, and medicine. Oxygen is important to live, and it is a big business.
Properties of Oxygen
Oxygen is usually described as a colorless, odorless, tasteless gas that is essential to live organisms. Given the proper conditions for the reactions, oxygen reacts with virtually every known element to produce oxides. Oxygen heads up the Group-VIA elements on the periodic table. The other members of this oxygen group are sulfur (S), selenium (Se), tellurium (Te), and polonium (Po). All except polonium are relatively plentiful in nature. There are two allotropes of oxygen, one composed of two oxygen molecules (02) and the other composed of three (03), the latter is known as ozone.
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