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Organic Chemistry for Hydrocarbon . Alkanes. Hydrocarbon chains where all the bonds between carbons are single bonds Name uses the ending – ane Examples: Meth ane , Prop ane , But ane , Oct ane , 2-methylpent ane. Prefixes for Carbons. Physical & Chemical Properties Alkanes Alkenes
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Alkanes • Hydrocarbon chains where all the bonds between carbons are single bonds • Name uses the ending –ane • Examples: Methane, Propane, Butane, Octane, 2-methylpentane
Physical & Chemical Properties • Alkanes • Alkenes • Alkynes • Aromatics
Physical & Chemical Properties • Alkanes & Cycloalkanes
Physical Properties of Alkanes and Cycloalkanes • Boiling points of unbranched alkanes increase smoothly with number of carbons • Melting points increase in an alternating pattern according to whether the number of carbon atoms in the chain is even or odd
Physical Properties of Alkanes and Cycloalkanes • Branched chain has higher boiling point than strength chain (in case of number of carbon is equal) • Alkanes are non-polar molecules, this indicates that alkanes are water-insoluble compounds. • Alkanes are non-conductive compounds.
1. Chemical Properties of Alkanes and Cycloalkanes • Alkanes & cycloalkanes • are well flammable. • no soot from combustion.
Chemical Properties of Alkanes and Cycloalkanes Alkanes & cycloalkanes are saturated compounds. (having only single bonds) Chemical reactions: Substitution reactions
Chemical Properties of Alkanes and Cycloalkanes 2. Halogenation is a chemical reaction that incorporates a halogen atom into a molecule. More specific descriptions exist that specify the type of halogen:fluorination, chlorination, bromination, and iodination light CH4 + Cl2 CH3Cl + HCl chlorination light C7H10 + Br2 C7H9Br + HBr bromination *light is a necessary factor to make a reaction*
Chemical Properties of Alkanes and Cycloalkanes • Alkanes & Cycloalkanes cannot be reacted and reduced color of KMnO4. Note! light + Br2 Br-CH2-CH2-CH2-Br Addition reaction light + Cl2 Cl-CH2-CH2-CH2-CH2-Cl Unstables alicyclic alkanes: more reacitivity
Physical & Chemical Properties • Alkenes & Cycloalkenes
Physical Properties of Alkenes and Cycloalkenes • Boiling points and melting point of alkenes increase with number of carbons. If no. of carbon is same, alkenes have less boiling point and melting point than alkanes, i.e., b.p. of C4H10 >C4H8 • Alkenes are non-water soluble compounds, but can soluble in non-polar solvent i.e. ether, hexane • Alkenes are non-conductive compounds.
Chemical Properties of Alkenes and Cycloalkenes 1. Combustion reaction 2C5H10 +15O2 10CO2 + 10H2O +heat 2. Addition reaction addition at double bond of carbon atom 2.1 Halogenation – halide addition, not required light CH2=CH2 + Cl2 Cl-CH2-CH2-Cl
Chemical Properties of Alkenes and Cycloalkenes 2.2 Hydrogenation – hydrogen addition with Ni or Pt acted as catalyst, alkanes will be obtained. Ni CH3-CH=CH2 + H2 CH3-CH-CH2 H H 2.3 Hydrohalogenation – acid halide addition and alkyl halide will be obtained CH2=CH2 + HCl H-CH2-CH2-Cl
Chemical Properties of Alkenes and Cycloalkenes 2.4 Hydration – water addition with H2SO4 acted as catalyst, alcohols will be obtained. H2SO4 CH2=CH2 +H2O HO-CH2-CH2-OH 3. Oxidation reaction react with KMnO4 (Oxidizing agent) in water, glycol will be obtained. 2KMnO4 + 4H2O + CH3-CH=CH-CH3 3CH3-CH-CH-CH3 + 2MnO2 + 2KOH OH OH
Physical & Chemical Properties • Alkynes
Physical Properties of Alkynes • Boiling points and melting point of alkenes increase with number of carbons. If no. of carbon is same: boiling point of alkynes > alkanes > alkenes • Alkynes are non-water soluble compounds, but can soluble in non-polar solvent i.e. ether, hexane
Chemical Properties of Alkynes 1. Combustion reaction 2C2H2 +5O2 4CO2 + 2H2O +heat 2. Addition reaction addition at triple bond of carbon atom 2.1 Halogenation – halide addition, not required light CHCH + Cl2 Cl-CH=CH-Cl Cl-CH=CH-Cl + Cl2 Cl-CH-CH-Cl Cl Cl
Chemical Properties of Alkynes 2.2 Hydrogenation – hydrogen addition with Ni or Pt acted as catalyst. Ni HCCH + 2H2 CH3-CH3 2.3 Hydrohalogenation – acid halide addition and alkyl halide will be obtained CHCH + HCl H-CH=CH-Cl H-CH=CH-Cl + HClH-CH-CH-Cl H Cl
Chemical Properties of Alkynes • 2.4 Hydration – water addition with H2SO4 acted as catalyst, • alcohols will be obtained if reactant is ethyne. • H2SO4O • CHCH +H2O H-CH2-C-H • Normally, ketones will be obtained. • H2SO4O • CH3-CCH +H2O CH3-C-CH3
Chemical Properties of Alkynes • 3. Oxidation reaction • react with KMnO4 (Oxidizing agent) in water • Carboxylic acid and CO2 will be obtained for alkyne with primary carbon • 3CHCH + 8KMnO4 + 4H2O 3HCOOH + 3CO2 + 8MnO2 + 8KOH • Ketone will be obtained for alkyne with secondary carbon • O O • 3RCCR + 4KMnO4 +2H2O 3R-C-C-R + 4MnO2 + 4KOH
Physical & Chemical Properties • Aromatic compounds
Physical Properties of Aromatics • Non-water soluble compounds • Soluble in non-polar organic solvent i.e. ether • Low boiling point and melting point • Individual odor compounds
15 2 Chemical Properties of Aromatics 1. Combustion reaction + O2 6CO2 + 3H2O 2. Substitution reaction 2.1 Halogenation – halide substitute with FeCl3 as catalyst FeCl3 Cl + Cl2 + HCl
Chemical Properties of Aromatics 2.2 Hydrogenation Under high pressure and temperature with Ni as catalyst + 3H2 2.3 Alkylation Alkyl group substitute by alkyl halide to hydrogen with AlCl3 as catalyst CH3 AlCl3 + CH3Br + HBr
Naming of Aromatic compounds CH3 H3C CH3 CH3 C2H5 CH3
Hexane CH3 CH2 CH2 CH CH3 CH3 Isohexane CH3 CH2 CH2 CH2 CH2CH3 Isomers Compounds that have the same molecularformula, but different molecular structures, are called structural isomers C6H14 straight chain C6H14 Branched chain alkanes
CH3 Isomers Differences compounds Same compounds
Isomers C5H12 C4H8 C3H8O Dichlorocyclomethane Trichlorocyclomethane
Functional compounds Identify the functional group of following compounds CH3CH2CH2COOH C3H7OH HCOH CH3COOCH2CH3