3I. Organic Compounds: defined Contains carbon which must have four bondsHave covalent bonds.Have low melting points.Have low boiling points.React slowly because of their complex bonding.May have symmetrical shapes (i.e.: tetrahedral) therefore are soluble in non-polar solvents.Form large molecules with triple, double and single bonds.
4II. Nomenclature: Naming Organic Compounds Learn to use Table P
5a) Types of Organic Compounds Hydrocarbonsany compound that contains carbon and hydrogen1. Alkanes – hydrocarbons that contains all single bonds among the carbons in any chain-Formula For Alkane CnH2n+2
6Complete Structural Formulas Show the bonds between each of the atomsH H H C H H C HCH4 , methaneIn methane, CH4 the four valence electrons of carbon are shared with the single electrons of four hydrogen (H) atoms. Each pair of electrons is a single bond, which can be drawn as a line. When a structure is drawn to show each bond, it is called a complete structural formula.
7More Alkanes H H Condensed Structural Formulas H C C H CH3 CH3 H H EthaneH H HH C C C H CH3 CH2 CH3H H H PropaneThe complete structural formula for ethane shows the single bonds between two carbon atoms and six H atoms. The complete structural formula of propane shows the 3-carbon chain with single bonds to the attached H atoms. To write a condensed structural formula, the H atoms are written as a group next to their respective C atoms.
8Alkane Family Molecular Formula CH4 Name # carbons Structural Formula Methane CH4Molecular FormulaCH4The names of organic compounds are determined by the IUPAC rules (International Union of Pure and Applied Chemistry). The stem of the name states the number of carbon atoms in the carbon chain of the compounds. The suffix, in this case –ane, indicates the alkane family.
9Alkane Family Continued Name # carbons Structural FormulaEthane CH3CH3Molecular FormulaC2H6
10Alkane Family Continued Name # carbons Structural FormulaPropane CH3CH2CH3Molecular FormulaC3H8
12Answer the following A. Draw butane? H H H H H C C C C H What is its molecular formula?C4H10
13b) Alkenes – unsaturated hydrocarbons that contain one double bond among the carbons in any chain. NameStructureMolecular FormulaC2H4EtheneC3H6PropeneButeneC4H8
14Answer the Following Why? H H H H H C= C-C-C- C H What is the molecular formula of pentene ?C5H10Why?H H H H HC= C-C-C- C HH H H H
15c) Alkynes- unsaturated hydrocarbons with one triple bond among the carbons in any chain NameStructureMolecular FormulaEthyne(acetyleneC2H2PropyneC3H4
16Naming Alkenes and Alkynes When the carbon chain has 4 or more C atoms, number the chain to give the lowest number to the double or triple bond.CH2=CHCH2CH31-buteneCH3CH=CHCH32-buteneCH3CCCH32-butyne
18Saturated and Unsaturated Compounds Saturated compounds (alkanes) have the maximum number of hydrogen atoms attached to each carbon atomUnsaturated compounds have fewer hydrogen atoms attached to the carbon chain than alkanesUnsaturated compounds contain double or triple bonds
19Summary of Hydrocarbons Alkanes, Alkenes and Alkynes are members of a homologous series where each successive member has one more carbon and two more hydrogensIf you arrange the series in alphabetical orderwhich comes first , second and third ?Alkane – single bondsAlkene – double bondAlkyne – triple bond
20Using the summary and the reference tables answer the following 1. Given CH4, C2H6,what is the next member ?C3H82. Which of the following has a double bond ?C4H10, C4H8 or C4H63. Which of the following is Pentyne ?C5H12 C3H4 C5H84. Which of the following is a saturated hydrocarbon ?5. Draw 2-butene.C-C=C-C plus the Hs
21Answer the following: What is the formula of Butene ? C4H8 What is the formula of HexaneC6H14What is the formula of Butyne ?C4H6Which of the following is an alkene ?C4H10 C4H6 or C4H8
22d) Benzene Series 1. Characteristics: Aromatic hydrocarbon (ring structures)Contains alternating double bondsDisplays chemical resonanceHighly nonpolar due to the depolarization of shared electron (equally distributed).Formula: CnH2n-6Examples: Benzene, Toluene, Napthalene