5 3 Organic Compounds Organic compounds contain carbon

5. 3 Organic Compounds • Organic compounds contain carbon and usually hydrogen. w “Organic” sounds like the compounds come from living things, but some do, and some do not. w Inorganic compounds are compounds that do not have carbon. w Carbon has four electrons in its valence shell, which allows for more chemical bonding possibilities than any other element. § Long chains of carbons form petroleum and plastics. w Organic molecules always have C before H in their formulas. § This differentiates organic compounds from acids, See pages 244 - 246 which almost always start with H. (c) Mc. Graw Hill Ryerson 2007

Hydrocarbons and Alcohols • A hydrocarbon is an organic compound that contains only carbon and hydrogen. w Hydrocarbons are based on a carbon chain, with hydrogen atoms added on the sides. w The simplest hydrocarbon is methane (CH 4), followed by ethane (C 2 H 6), propane (C 3 H 8), butane (C 4 H 10), and pentane (C 5 H 12). w All hydrocarbons are flammable, and most are liquids are room temperature. • Alcohols are organic compounds with C, H, and O. w The simplest alcohols are methanol (CH 4 O), ethanol (C 2 H 6 O), and isopropyl alcohol (C 3 H 8 O). w Alcohols are very good solvents (they dissolve other substances). w Alcohols are generally very flammable. See pages 246 - 247 Take the Section 5. 3 Quiz (c) Mc. Graw Hill Ryerson 2007

Review In Chemistry, an organic compound is one containing carbon atoms. Carbon is special because a single carbon atom is capable of combining with up to four other atoms (valence of four = maximum of four bonds). Carbon can combine with many other carbon atoms making large molecules. This means that carbon atoms can form chains and rings onto which other atoms can be attached.

Chains of Carbon Atoms The simplest Organic compounds are made up of only carbon and hydrogen atoms only and are called hydrocarbons. Names of simple chains of hydrocarbons are given names based on the number of carbon atoms in the molecule. Prefixes are used to denote the number carbon atoms. Alkane hydrocarbons consist of carbon and hydrogen atoms linked together with single bonds.

Alkane Hydrocarbons C methane C-C-C propane C-C-C-C butane C-C-C pentane C-C-C-C hexane C-C-C-C heptane

C-C-C-C-C octane C-C-C-C-C nonane C-C-C-C-C-C decane C-C-C-C-C-C undecane C-C-C-C-C-C-C dodecane