Hydrocarbon Compounds 22.1 Hydrocarbons 22.2 Unsaturated Hydrocarbons 22.3 Isomerism 22.4 Hydrocarbon Rings 22.5 Hydrocarbons from Earth’s Crust Updated 11/11/2018 Created by C. Ippolito July 2007

Created by C. Ippolito July 2007 Hydrocarbons Objectives Describe the relationship between the number of valence electrons and bonding in carbon Define and describe alkanes Relate the polarity of hydrocarbons to their solubility Updated 11/11/2018 Created by C. Ippolito July 2007

Organic Chemistry and Hydrocarbons originally compounds thought to be made only in living things now study of compounds with BOTH carbon and hydrogen Hydrocarbons simplest organic compounds contain only carbon and hydrogen Updated 11/11/2018 Created by C. Ippolito July 2007

Created by C. Ippolito July 2007 Alkanes only single covalent bonds between carbons Saturated Hydrocarbons contain the maximum number of hydrogen atoms per carbon atom Straight Chain Alkanes homologous series – group of compounds that have a constant incremental change 1 = meth- 3 = prop- 5 = pent- 7 = hept- 9 = non- 2 = eth- 4 = but- 6 = hex- 8 = oct- 10 = dec- Updated 11/11/2018 Created by C. Ippolito July 2007

Created by C. Ippolito July 2007 Formulas Molecular Formula – C4H10 Structural Formula – Condensed Structural Formulas CH3-CH2-CH2-CH3 CH3CH2CH2CH3 CH3(CH2)2CH3 Carbon Skeleton – C-C-C-C Line Angle Formula - section 1 Updated 11/11/2018 Created by C. Ippolito July 2007

Created by C. Ippolito July 2007 Branched Chains Parent Chain longest continuous carbon chain Substituents atoms or atom groups replacing a hydrogen atom Alkyl Groups hydrocarbon substituents CH3― methyl group CH3CH2― ethyl group CH3CH2CH2― propyl group Updated 11/11/2018 Created by C. Ippolito July 2007

IUPAC Naming Rules for Alkanes Find longest chain (parent) Number carbons and use root name with –ane ending Add numbers to substituent groups Use prefixes for multiple appearances of same group List substituents in alphabetical order Use punctuation but no spaces Updated 11/11/2018 Created by C. Ippolito July 2007

Naming Branched Alkanes Updated 11/11/2018 Created by C. Ippolito July 2007

Drawing Branched-Chain Alkanes Updated 11/11/2018 Created by C. Ippolito July 2007

Created by C. Ippolito July 2007 Properties of Alkanes Hydrocarbons are NONPOLAR weak van der Waals forces low mass tend to be gases or liquids with low boiling points insoluble in water Updated 11/11/2018 Created by C. Ippolito July 2007

Unsaturated Hydrocarbons Objectives Describe the difference between unsaturated and saturated hydrocarbons Distinguish between the structures of alkenes and alkynes Updated 11/11/2018 Created by C. Ippolito July 2007

Created by C. Ippolito July 2007 Alkenes contain one or more carbon-carbon double covalent bond Unsaturated Hydrocarbon contain less than the maximum number of hydrogen per carbon atom Updated 11/11/2018 Created by C. Ippolito July 2007

IUPAC Naming Rules for Alkenes Find longest chain with double bond (parent) Number carbons and use root name with ending –ene so that double bond has lowest number possible Add numbers to substituent groups Use prefixes for multiple appearances of same group List substituents in alphabetical order Use punctuation but no spaces Updated 11/11/2018 Created by C. Ippolito July 2007

Created by C. Ippolito July 2007 Alkenes contain one or more carbon-carbon triple covalent bond Unsaturated Hydrocarbon contain less than the maximum number of hydrogen per carbon atom Updated 11/11/2018 Created by C. Ippolito July 2007

IUPAC Naming Rules for Alkynes Find longest chain with triple bond (parent) Number carbons and use root name with ending –yne so that double bond has lowest number possible Add numbers to substituent groups Use prefixes for multiple appearances of same group List substituents in alphabetical order Use punctuation but no spaces Updated 11/11/2018 Created by C. Ippolito July 2007

Created by C. Ippolito July 2007 Isomerism Objectives Explain why structural isomers have different properties Describe the conditions under which geometric isomers are possible Identify optical isomers Updated 11/11/2018 Created by C. Ippolito July 2007

Created by C. Ippolito July 2007 Structural Isomers compounds with the same molecular formula but different structures different physical and chemical properties section 2 May 1 section 3 May 2 Updated 11/11/2018 Created by C. Ippolito July 2007

Created by C. Ippolito July 2007 Stereoisomers atoms joined in same order but positions in space are different Geometric Isomers related to rigid double bond Optical Isomers asymmetrical carbon Updated 11/11/2018 Created by C. Ippolito July 2007

Created by C. Ippolito July 2007 Geometric Isomers Geometric Isomers orientation around rigid double bond cis configuration groups on same side of double bond trans configuration groups on different sides of double bond Updated 11/11/2018 Created by C. Ippolito July 2007

Created by C. Ippolito July 2007 Optical Isomers Optical Isomers four different groups attached to an asymmetric carbon Updated 11/11/2018 Created by C. Ippolito July 2007

Objectives Identify cyclic ring structures Describe bonding in benzene Hydrocarbon Rings Objectives Identify cyclic ring structures Describe bonding in benzene Updated 11/11/2018 Created by C. Ippolito July 2007

Created by C. Ippolito July 2007 Cyclic Hydrocarbons hydrocarbon chain forms a ring cyclopropane cyclobutane cyclopentane cyclohexane section 1 May 3 Updated 11/11/2018 Created by C. Ippolito July 2007

Aromatic Hydrocarbons contains a benzene ring electrons shared evenly “resonance” phenyl group benzene sub Updated 11/11/2018 Created by C. Ippolito July 2007

Created by C. Ippolito July 2007 Substituted Benzene dimethyl benzene – 3 isomers ortho- 1,2 dimethyl benzene o-xylene meta- 1,3 dimethyl benzene m-xylene para- 1,4 dimethyl benzene p-xylene may 3 section 2 Updated 11/11/2018 Created by C. Ippolito July 2007

Hydrocarbons from Earth’s Crust Objectives Identify three important fossil fuels and describe their origins. Describe the composition of natural gas, petroleum, and coal. Describe what happens when petroleum is refined Updated 11/11/2018 Created by C. Ippolito July 2007

Created by C. Ippolito July 2007 Natural Gas source of alkanes of low molar mass 80% methane 10% ethane 4% propane CH4(g) + 2O2(g)  CO2(g) + 2H2O(g) + heat Updated 11/11/2018 Created by C. Ippolito July 2007

Created by C. Ippolito July 2007 Petroleum Fractional Distillation separation by boiling points Cracking heat to form smaller chains from larger ones Updated 11/11/2018 Created by C. Ippolito July 2007

Created by C. Ippolito July 2007 Coal Classified by its hardness and carbon content Peat soft, brown, spongy, fibrous material high water content Lignite harder, less fibrous, 50% carbon Bituminous Coal “soft” coal, 70%-80% carbon Anthracite Coal “hard” coal, over 80% carbon Updated 11/11/2018 Created by C. Ippolito July 2007