Ethane is a molecule made up of two carbon atoms joined in a single bond. Each carbon atom is bonded to three hydrogen atoms. Ethene is made of two carbon atoms joined in a double bond. Each carbon atom is joined to two hydrogen atoms. Ethyne is made of two carbon atoms joined in a triple bond. Each carbon atom is joined in a single bond to a hydrogen atom.
Because ethene, ethane and ethyne are made up of carbon and hydrogen atoms, they are called hydrocarbons. All three are flammable gases. Their flammability depends on the types of bonds shared by the carbon atoms. Ethane is the least flammable, while ethene is more flammable and ethyne, also called acetylene, is explosively flammable.
Acetylene is favored in welding because it produces a very intense flame. When mixed with oxygen, an acetylene flame can reach temperatures over 6,000 degrees Fahrenheit.
Ethane is colorless and odorless, and its main function is to produce ethene, which is also known as ethylene. Ethylene is also colorless, but some claim that it has a slight musky/sweet smell. People recognize ethylene as the gas that is added to picked, unripe fruit to hasten the fruit's ripening.