Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Chapter 10 Introduction to Organic Chemistry: Alkanes 10.1 Organic Compounds 1

Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Organic Chemistry An organic compound is a compound made from carbon atoms has one or more C atoms has many H atoms may also contain O, S, N, and halogens usually has carbon written first 2

Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Organic Compounds Typical organic compounds have covalent bonds have low melting points have low boiling points are flammable are soluble in nonpolar solvents are not soluble in water Vegetable oil is an organic compound and not soluble in water. 3

Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Organic vs. Inorganic Propane, C 3 H 8, is an organic compound used as a fuel. NaCl, salt, is an inorganic compound composed of Na + and Cl  ions. Why is propane organic, but NaCl is not? 4

Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Comparing Organic and Inorganic Compounds 5

Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Learning Check Identify each characteristic as most typical of compounds that are inorganic or organic. A. Has a high melting point B. Is not soluble in water C. Has the formula CH 3  CH 2  CH 3 D. Has the formula MgCl 2 E. Burns easily in air F. Has covalent bonds 6

Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solution Identify each characteristic as most typical of compounds that are inorganic or organic. A. Has a high melting pointinorganic B. Is not soluble in waterorganic C. Has the formula CH 3  CH 2  CH 3 organic D. Has the formula MgCl 2 inorganic E. Burns easily in airorganic F. Has covalent bondsorganic 7

Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Bonding in Organic Compounds In organic compounds, carbon has 4 valence electrons and hydrogen has 1 carbon achieves an octet by forming four bonds, with each line representing 2 electrons CH 4, methane 8

Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Tetrahedral Structure of Carbon CH 4 VSEPR theory predicts that a carbon atom with four single, covalent bonds has a tetrahedral shape. Methane is represented using different models: (a) tetrahedron, (b) ball-and- stick model, (c) space-filling model, (d) expanded structural formula. 9

Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Tetrahedral Structure of Carbon C 2 H 6 In ethane, each carbon forms covalent bonds to another carbon and three hydrogen atoms each carbon atom retains its tetrahedral shape Ethane, CH 3 ─CH 3 10

Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. In molecules with two or more carbon atoms, each carbon atom with four single bonds has a tetrahedral shape. Representations of ethane: (a) tetrahedral shape of each carbon, (b) ball-and-stick model, (c) space-filling model, (d) expanded structural formula. 11 Tetrahedral Structure of Carbon C 2 H 6

Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Learning Check In the butane molecule, C 4 H 10, predict the shape around each carbon atom. 12

Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solution In the butane molecule, C 4 H 10, predict the shape around each carbon atom. Each carbon atom has four single covalent bonds and therefore a tetrahedral shape. 13