1 AP Chemistry Chapter 22 - Organic Chemistry 22.1 Alkanes: Saturated Hydrocarbons A. Straight-chain Hydrocarbons 1. Straight-chain alkanes have the formula CnH2n+2 2. Carbons are sp3 hybridized The First 10 Alkanes # of Carbons Name Formula (CnH2n+2) 1 Methane CH4 2 Ethane C2H6 3 Propane C3H8 4 Butane C4H10 5 Pentane C5H12 6 Hexane C6H14 7 Heptane C7H16 8 Octane C8H18 9 Nonane C9H20 10 Decane C10H22 B. Structural Isomers 1. Same formula, but the atoms are bonded together in a different order 2. Different bonding order results in different properties C4H10 Butane C4H10 2-methylpropane C. Rules for Naming Alkanes (Nomenclature) 1. For a branched hydrocarbon, the longest continuous chain of carbon atoms