Presentation is loading. Please wait.

Presentation is loading. Please wait.

Organic Compounds. Typical organic compounds: Contain carbon Have covalent bonds Have low melting points Have low boiling points Are flammable (all burn)

Similar presentations


Presentation on theme: "Organic Compounds. Typical organic compounds: Contain carbon Have covalent bonds Have low melting points Have low boiling points Are flammable (all burn)"— Presentation transcript:

1 Organic Compounds

2 Typical organic compounds: Contain carbon Have covalent bonds Have low melting points Have low boiling points Are flammable (all burn) Are soluble in nonpolar solvents May be gases, liquids or solids C 3 H 8 Propane

3 –Carbon: normally forms four covalent bonds and has no unshared pairs of electrons. –Hydrogen: forms one covalent bond and no unshared pairs of electrons. –Nitrogen: normally forms three covalent bonds and has one unshared pair of electrons. –Oxygen: normally forms two covalent bonds and has two unshared pairs of electrons. –Halogen: normally forms one covalent bond and has three unshared pairs of electrons. C H N O = Cl......

4 An atom or group of atoms within a molecule that shows a characteristic set of predictable physical and chemical properties. –A way to classify families of organic compounds. –They determine the chemical and physical properties of a molecule. –They undergo the same types of chemical reactions. –A way to name organic compounds. Functional groups

5 Hydrocarbons Large family of organic compounds Composed of only carbon and hydrogen Saturated hydrocarbons Alkanes Unsaturated hydrocarbons Alkenes, Alkynes & Aromatics C - C C = CC

6 Carbon Carbon has four valence electrons; hydrogen has one. C H To obtain an octet, carbon forms four bonds. H H  C  HH C HCH 4, methane H H H

7 Alkanes

8 Methane Tetrahedral Expanded structural formula: showing each bond line. CH 4 Molecular formula

9 Ethane C2H6C2H6 Molecular formula Expanded structural formula CH 3 – CH 3 Condensed structural formula: with each carbon atom and its attached hydrogen atoms.

10 Alkanes C n H 2n+2 n: number of carbon atoms

11 Naming of Alkanes C n H 2n+2 Prefix + ane

12 Line-angle Formula CH 3 -CH 2 -CH 2 -CH 2 -CH 3 Propane Butane Pentane CH 3 -CH 2 -CH 2 -CH 3 CH 3 -CH 2 -CH 3

13 In the IUPAC system: Removing a H from an alkane is called alkyl group. -ane Halogen atoms are named as halo. -ine Naming Substituents -OHHydroxyl -NO 2 Nitro -yl -O

14

15 Give the name of: CH 3  CH 3 ─CH─CH 2 ─CH 3 STEP 1 Longest chain is butane. STEP 2 Number chain. CH 3  CH 3 ─CH─CH─CH STEP 3 Locate substituents and name. 2-Methylbutane

16 Give the name of: CH 3 CH 3  CH 3 ─CH─CH─CH 3 STEP 1 Longest chain is butane. STEP 2 Number chain. CH 3 CH 3  CH 3 ─CH─CH─CH STEP 3 Locate substituents and name. 2,3-dimethylbutane

17 STEP 1 Longest chain is pentane. STEP 2 Number chain from end nearest substituent. Cl CH 3  CH 3 ─CH 2 ─CH─CH─CH STEP 3 Locate substituents and name alphabetically. 3-chloro-2-methylpentane Cl CH 3  CH 3 ─CH 2 ─CH─CH─CH 3

18 CH 3 CH 3 | | CH 3 ─CH─CH 2 ─CH─CH 3 2,4-dimethylpentane Cl CH 3 | | CH 3 ─CH 2 ─CH─CH 2 ─C─CH 2 ─CH 3 | Cl ,5-dichloro-3-methylheptane

19 Br  CH 3 ─CH─CH 2 ─CH 2 ─Cl STEP 1 Longest chain has 4 carbon atoms. C─C─C─C STEP 2 Number chain and add substituents. Br  C ─ C ─ C ─ C ─ Cl STEP 3 Add hydrogen to complete 4 bonds to each C. Br  CH 3 ─CH─CH 2 ─CH 2 ─Cl 2-bromo-4-chlorobutane

20 Constitutional Isomers Have the same molecular formula. Have different atom arrangements (different structural formula). CH 3 CH 2 CH 2 CH 3 Butane CH 3 CHCH 3 2-Methylpropane CH 3 C 4 H 10

21 = = = Cyclic Hydrocarbon - Cycloalkane Cyclobutane Cyclopentane Cyclohexane

22 Nonpolar Insoluble in water. Lower density than water. Low boiling and melting points. Gases with 1-4 carbon atoms. (methane, propane, butane) Liquids with 5-17 carbon atoms. (kerosene, diesel, and jet fuels) Solids with 18 or more carbon atoms. (wax, paraffin, Vaseline) Physical Properties of Alkanes

23 Boiling & melting points of Alkanes Number of carbon atoms ↑ bp & mp ↑ Number of branches ↑ bp & mp ↓ CH 3 CH 2 CH 2 CH 3 CH 3 CHCH 3 CH 3

24 Chemical reactions of Alkanes Low reactivity 1- Combustion: Alkanes react with oxygen. CO 2, H 2 O, and energy are produced. Alkane + O 2 CO 2 + H 2 O + heat CH 4 + 2O 2 CO 2 + 2H 2 O + energy

25 2- Halogenation: Alkanes react with Halogens. CH 4 + Cl 2 CH 3 Cl + HCl Heat or light Chemical reactions of Alkanes Low reactivity CH 3 Cl+ Cl 2 CH 2 Cl 2 + HCl CH 2 Cl 2 + Cl 2 CHCl 3 + HCl CHCl 3 + Cl 2 CCl 4 + HCl Heat or light Chloromethane Dichloromethane Trichloromethane Tetrachloromethane

26 Natural gas –90 to 95 percent methane –5 to 10 percent ethane, and –a mixture of other low-boiling alkanes, chiefly propane, butane, and 2- methylpropane. Petroleum –A thick liquid mixture of thousands of compounds, most of them hydrocarbons formed from the decomposition of marine plants and animals. Sources of Alkanes

27 Alkenes and Alkynes

28 Saturated compounds (alkanes): Have the maximum number of hydrogen atoms attached to each carbon atom. Unsaturated compounds: Have fewer hydrogen atoms attached to the carbon chain than alkanes. Containing double bond are alkenes. C n H 2n Containing triple bonds are alkynes. C n H 2n-2 Alkenes and Alkynes

29 Using the IUPAC alkane names: Alkene names change the end to -ene. Alkyne names change the end to -yne Naming Alkenes & Alkynes

30 Give the location for double and triple bond

31 CH 2 = CH ─ CH 2 ─ CH 3 1-butene CH 3 ─ CH=CH─ CH 3 2-butene CH 3 | CH 3 ─ CH=C─CH 3 2-methyl-2-butene CH 3 ─ C  C ─ CH 3 2-butyne Naming Alkenes & Alkynes

32 CH 3 ─ CH 2 ─ C  C ─ CH 3 2-pentyne CH 3 CH 3 ─ CH 2 ─ C=CH ─ CH 3 3-methyl-2-pentene CH 2 – CH 3 CH 3 ─ CH 2 ─ C=CH ─ CH 3 3-ethyl-2-pentene Naming Alkenes & Alkynes

33 Chemical properties of Alkenes & Alkynes More reactive than Alkanes Addition of Hydrogen (Hydrogenation-Reduction) Addition of Hydrogen Halides (Hydrohalogenation) Addition of water (hydration) Addition of Bromine & Chlorine (Halogenation)

34 A hydrogen atom adds to each carbon atom of a double bond. A catalyst such as platinum is used. H H H H │ │ Pt │ │ H–C=C–H + H 2 H– C – C– H │ │ H H ethene ethane Chemical properties Hydrogenation: Pt More reactive than Alkanes

35 A halogen atom adds to each carbon atom of a double bond. Usually by using an inert solvent like CH 2 Cl 2. H H H H │ │ │ │ CH 3 –C=C–CH 3 + Cl 2 CH 3 – C – C– CH 3 │ │ Cl Cl 2-Butene 2,3-Dichlorobutane Chemical properties Halogenation: CH 2 Cl 2 More reactives than Alkanes

36 Aromatic Hydrocarbons

37 Aromatic compounds contain benzene. Benzene has: 6 C atoms and 6 H atoms. Two possible ring structures. Aromatic Compounds

38 Arene: A compound containing one or more benzene rings. Aromatic compounds are named: With benzene as the parent chain. Name of substituent comes in front of the “benzene”. methylbenzene chlorobenzene ethylbenzene CH 3 Cl CH 2 -CH 3

39 Naming of Aromatic Compounds Some substituted benzenes have common names. CH 3 Toluene

40 Naming of Aromatic Compounds When two groups are attached to benzene, the ring is numbered to give the lower numbers to the substituents. -Start numbering from special name (if we have). -If we do not have, number them to get the smallest set of numbers. -Name them by alphabetical order. OrthoMetaPara 3-methyltoluene

41 Naming of Aromatic Compounds If we have three or more substituents: -Start numbering from special name (if we have). -If we do not have, number them to get the smallest set of numbers. -Name them by alphabetical order.

42 Chemical properties of benzene Halogenation Nitration Sulfonation Resonance: stable No addition reactions (almost unreactive)

43 Chemical properties of benzene Halogenation Nitration

44 Review Work through the Sample Problems pages 179, 180 Complete the revision questions page 181 (24 – 28)


Download ppt "Organic Compounds. Typical organic compounds: Contain carbon Have covalent bonds Have low melting points Have low boiling points Are flammable (all burn)"

Similar presentations


Ads by Google