Hydrocarbons are a class of organic compounds consisting entirely of hydrogen and carbon. Hydrocarbons are generally colourless and hydrophobic with only weak odours. Hydrocarbons are the principal constituents of petroleum and natural gas. They are used as fuels and lubricants as well as raw materials for the production of plastics, fibres, rubbers, solvents, explosives and industrial chemicals. Methane, ethane, propane, butane, etc., are examples of some common hydrocarbons.

Flame is a region where the combustion of gaseous substances takes place. It is the visible gaseous part of the fire. The colour of the flame changes with the supply of oxygen. The flame is blue at the base and above when oxygen is freely available to the flame. The flame is yellow with red when the oxygen supply is not sufficient. The flame is yellow when the oxygen supply is poor.

Hydrocarbons are a class of organic compounds consisting entirely of hydrogen and carbon. Hydrocarbons are generally colourless and hydrophobic with only weak odours. Hydrocarbons are the principal constituents of petroleum and natural gas. They are used as fuels and lubricants as well as raw materials for the production of plastics, fibres, rubbers, solvents, explosives and industrial chemicals. Methane, ethane, propane, butane, etc., are examples of some common hydrocarbons.