What is meant by saturated and unsaturated carbon compounds

WHAT IS MEANT BY SATURATED AND UNSATURATED CARBON COMPOUNDS  

Alkenes are called unsaturated because they contain a C=C double bond and therefore less hydrogen than the corresponding alkanes. They can undergo addition reactions in order to become saturated . The alkanes have no double bonds and all their bonds are sigma bonds between C-C and C-H. They cannot undergo addition reactions because they are saturated already. An even more unsaturated series of hydrocarbons is the alkynes, C H2 -2, which contain a carbon-carbon triple bond, (C=C), made up of a sigma and two pi bonds. The best known member of this series is C2H2, ethyne (also known as acetylene). 

All hydrocarbons will bum in air or oxygen to produce carbon dioxide and water. All give out heat when they bum, le. the reaction is exothermic. 

The reaction requires a spark or a flame to start the burning, but once started it continues on its own and gives out heat. So hydrocarbons (particularly the lighter members of the series) are all potentially good f uels. 

You will be aware that North Sea gas consists mainly of methane. Propane and butane are used as bottled gas, camping gas or in cigarette lighters (when under pressure both propane and butane are liquids). Because the burning process gives out heat, the exothermic reaction is put to commercial use  

---