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25-3: Hydrocarbons 25-4: Saturated and Unsaturated Hydrocarbons. Hydrocarbon. Organic molecule that contains only hydrogen and carbon Properties: All bonds are nonpolar, so molecule is nonpolar Are poor conductors Have low density Do not dissolve in water
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25-3: Hydrocarbons25-4: Saturated and Unsaturated Hydrocarbons
Hydrocarbon • Organic molecule that contains only hydrogen and carbon • Properties: • All bonds are nonpolar, so molecule is nonpolar • Are poor conductors • Have low density • Do not dissolve in water • Found deep within the Earth as natural gas and petroleum (fossil fuels)
Types of formulas • Molecular formula: gives symbols and numbers of atoms present • Ex: butane is C4H10 • Structural formula: shows how the atoms are bonded together in a two dimensional way • Butane • Condensed structural formula: shows only how carbon atoms are bonded • Butane CH3CH2CH2CH3
Alkanes • Hydrocarbons with only single bonds • Names end in –ane • General formula: CnH2n+2 • Is a saturated hydrocarbon; all carbon bonds are filled to capacity with hydrogens
Methane Ethane Propane Butane Pentane Hexane Heptane Octane Nonane decane CH4 C2H6 C3H8 C4H10 C5H12 C6H14 C7H16 C8H18 C9H20 C10H22 Alkane Series
Branched Alkanes • Identify the longest continuous carbon chain. This is the parent chain and is named as a regular alkane. • Identify the shorter chain. Give this chain a number (from the carbon that it is bonded to) and name it as an alkyl group (methyl, ethyl, propyl, butyl) • Examples
Conformations • Two structures that differ only by one or more bond rotations • Examples
Structural Isomers • Two structures that have the same molecular formula, but their atoms bond in different orders. • Examples
Cycloalkanes • Cyclic hydrocarbons: hydrocarbons that contain a carbon ring • If they contain all single bonds, then they are cycloalkanes
Unsaturated Hydrocarbons • Contain at least one double or triple bond between carbon atoms.
Alkenes • Contain at least one double bond. • General formula: CnH2n • In naming, name them just like alkanes, just give a number to designate the position of the double bond AND they end in –ene. • Example: apples produce ethene gas as they ripen.
Alkynes • Contain at least one triple bond. • General formula: CnH2n-2 • In naming, name them just like alkanes, just give a number to designate the position of the triple bond AND they end in –yne. • Ethyne is used in torches – also called acetylene.
Benzene • Draw it. • Compounds that have a benzene ring in it are called aromatic compounds (they usually smell good!) • Examples of aromatic compounds include: cloves, vanilla beans, and almonds.