Petroleum products, such as gasoline, kerosene, home heating oil, residual fuel oil and lubricating oils, come from one source - crude oil found below the Earth's surface, as well as under large bodies of water, from a few hundred feet below the surface to as deep as 25,000 feet into the earth's interior. Sometimes crude oil is secured by drilling into the Earth, but more dry holes are drilled than those producing oil. Either pressure at the source or pumping forces crude oil to the surface. Crude oil wells flow at varying rates, from ten to thousands of barrel per hour. Petroleum products are always measured in 42 gallon barrels. Petroleum products vary greatly in physical appearance: thin, thick, transparent or opaque, but regardless their chemical composition is made up of TO #2 Alphastude Literasi Bahasa Inggris only two elements: Carbon and Hydrogen, which form compounds called Hydrocarbons. Other chemical elements found in union with the hydrocarbons are few and are classified as impurities. Trace elements are also found, but in such minute quantities that they are disregarded. The combination of carbon and hydrogen forms many thousands of compounds which are possible because of the various positions and joinings of these two atoms in the hydrocarbon molecule. The various petroleum products are refined by heating crude oil and then condensing the vapours. These products are so-called light oils, such as gasoline, kerosene and distillate oil. The residue remaining after the light oils are distilled is known as heavy or residual fuel oil and is used mostly for burning under boilers. Additional complicated refining process rearrange the chemical structure of the hydrocarbons to produce other products, some of which are used to upgrade and increase the octane rating of various types of gasoline. 1. Many thousands of hydrocarbon compounds are possible because... A. The petroleum products vary greatly in physical appearance B. Complicated refining processes rearrange the chemical structure C. The two atoms in the molecule assume many positions D. The preassure needed to force it to the surface causes molecular transformation E. Chemical elements forming petroleum are many in number 2. All the following statements are true, except... A. Crude oil is found below land and water B. Crude oil is always found a few hundred feet below the surface C. Pumping and pressure force crude oil to the surface D. Many petroleum products are obtained from crude oil E. The chemical composition of petroleum is formed of only two elements 3. How is crude oil brought to the surface? A. Pressure and pumping B. Expansion of the hydrocarbons C. Vacuum created in the drilling pipe D. Expansion and contraction of the earth's surface E. Different pressure of surface and the earth's interio