Chapter 10 Introduction to Organic Chemistry Alkanes 10

Chapter 10 Introduction to Organic Chemistry: Alkanes 10. 4 Properties of Alkanes Copyright © 2005 by Pearson Education, Inc. Publishing as Benjamin Cummings 1

Some Properties of Alkanes are • nonpolar. • insoluble in water. • less dense than water. • flammable in air. 2

Some Properties of Alkanes with 1 -4 carbon atoms are • methane, propane, and butane. • gases at room temperature. • used as heating fuels. 3

Some Properties of Alkanes with 5 -8 carbon atoms are • liquids at room temperature. • pentane, hexane, heptane, and octane. • very volatile. • used to make gasoline. Alkanes with 9 -17 carbon atoms • are liquids at room temperature • have higher boiling points. • are found in kerosene, diesel, and jet fuels. 4

Some Properties of Alkanes with 18 or more carbon atoms • have high molar masses. • are waxy solids at room temperature. • used in waxy coatings of fruits and vegetables. 5

Melting and Boiling Points of Hydrocarbons 6

Combustion In combustion reactions, • alkanes react with oxygen. • CO 2, H 2 O and energy are produced. Alkane + O 2 CO 2 + H 2 O + heat 7

Learning Check Write a balanced equation for the complete combustion of propane. 8

Solution Unbalanced equation C 3 H 8 + O 2 CO 2 + H 2 O Balance C C 3 H 8 + O 2 3 CO 2 + H 2 O Balance H C 3 H 8 + O 2 3 CO 2 + 4 H 2 O Balance O C 3 H 8 + 5 O 2 3 CO 2 + 4 H 2 O (Balanced) 9