Ethane, ethene and ethyne molecules. Molecular models of ethane (C2H6, upper left), an alkane, ethene (C2H4, centre), an alkene, and ethyne (C2H2), an alkyne. Carbon atoms are black and hydrogen atoms are white. Ethane and ethene are both found in natural gas. Ethene is manufactured in larger quantities than any other organic chemical. It is produced naturally by fruits and accelerates the ripening of fruit. Ethyne is also known as acetylene. it is a starting chemical for many other chemicals and is used in oxy-acetylene welding. All three compounds form explosive mixtures with air.