The higher the number, the more anti-knock quality. Oil A mixture of liquid hydrocarbons of different molecular weights. A geographical area under which an oil reservoir lies.
Examples are ethylene and propylene.
OPEC The Organization of Petroleum Exporting Countries, which are Algeria, Indonesia, Iran, Iraq, Kuwait, Libya, Nigeria, Qatar, Saudi Arabia, United Arab Emirates and Venezuela. The legal right to produce oil or gas from a well, accompanied by the responsibilities to pay production costs and assume the risks. Orthoxylene An aromatic compound used in the manufacture of plasticizers and polyester. That portion of a continental land mass that constitutes the slope down to the ocean floor. The outer continental shelves are heavily sedimented, and it is believed they contain a large portion of the earth's undiscovered oil and gas.