http://www.sciencebold.com/wp-content/uploads/2016/07/Untitled-300x114.png 0 0 admin http://www.sciencebold.com/wp-content/uploads/2016/07/Untitled-300x114.png admin2011-09-25 10:54:002016-06-23 15:15:30Oxygen Gas
Molecular formula: O2
Molecular weight: 16
Oxygen is one of the abundantly available gases in air. It makes about 21% of atmosphere by volume. It is important to all the life on earth. It was discovered by a Swedish chemist Scheele in 1772 by heating red oxide of mercury and by Priestley of England in 1774. Antony Lavoisier of France studied its properties and named as ‘Oxygen’ in 1776. The credit of discovery goes to Joseph Priestley because his papers were published earlier.
Oxygen is available in free state in air. It forms a mixture with other gases to form air. In combined state, it is present in oxides. It combines with many elements to form compounds such as sugar, starch, fats and oils, acid, bases and salts. It is found in maximum quantity upon the earth in oxides of metals and non-metals.
Laboratory preparation of Oxygen (using heat)
1. Hard glass test-tube.
2. Delivery tube.
3. Trough with water
4. Gas jar
1. Potassium chlorate (KClO3)
2. Manganese dioxide (MnO2)