Organic Chemistry The study of carbon, hydrogen, oxygen and nitrogen containing compounds
Organic Chemistry
The study of carbon, hydrogen, oxygen and nitrogen containing
compounds
THE HYDROCARBONS
Characteristics contain only carbon and hydrogen non-polar molecules low boiling point - decompose easily sp3 hybridization insoluble in water (most) slow reactivity non-electrolytes (poor ionization)
NOMENCLATURE
The number of carbon atoms is determined by the root part of the name
• meth 1 carbon• eth 2 carbon• prop 3 carbon• but 4 carbon• pent 5 carbon• hex 6 carbon• hept 7 carbon• oct 8 carbon
The Alkanes
Characteristics saturated hydrocarbons (single bonds only) homologous series (follow same pattern) fewer # of carbons - lower boiling points follow same general formula - CnH2n+2
end in -ane
The Alkanes - Saturated hydrocarbonsMethane H
H C H CH4
H
Propane H H HH C C C H C3H8
H H H
Ethane H H H C C H C2H6
H H
Isomers - molecule has the SAME chemical formula, but DIFFERENTstructural formulaButane is the first hydrocarbon to exhibit isomerism.
n- Butane H H H H H C C C C H C4H10
H H H H
2-methyl propane (isobutane) H
H C H H HH C C C H C4H10 H H H
Naming : 1- find longest chain of C atoms and name it 2- name attached group 3- indicate the address of the attached group with number
n-pentane H H H H H H C C C C C H C5H12
H H H H H
2,2-dimethylpropane H(neopentane) H C H
H H H C C C H C5H12
H H H C H
H
2-methylbutane H(isopentane) H C H
H H H H C C C C H C5H12
H H H H
n-hexane H H H H H H H C C C C C C H C6H14
H H H H H H
n-heptane H H H H H H H H C C C C C C C H C7H16
H H H H H H H
n-octane H H H H H H H H H C C C C C C C C H C8H18
H H H H H H H H
Reactions of the Alkanes1. Combustion
Alkane + Oxygen Carbon dioxide + Water Ex.
CH4(g) + 2 O2(g) CO2 (g) + 2 H2O (g)
2. Halogen SubstitutionOne hydrogen from a saturated hydrocarbon is replaced by
a halogen atom forming a halogen substituted hydrocarbon.Ex.
C2H6 + Cl2 C2H5Cl + HCl Two products are always produced.
The Alkenes - Unsaturated hydrocarbons
Characteristics unsaturated hydrocarbons (1 double bond) homologous series (follow same pattern) fewer # of carbons - lower boiling points follow same general formula - CnH2n
end in -ene
The AlkenesEthene H H
C C C2H4
H H
Propene H H H H C C C C3H6
H H
Isomers - The isomers of the alkene series are identified by the placement of the double bond. The molecule is named by indicating the location (by number) of the double bond.
1-butene H H H H C C C C H C4H8
H H H
2-butene H H H H C C C C H C4H8
H H H
Reactions of the Alkenes1. Combustion
Alkene + Oxygen Carbon dioxide + Water
2. Addition A. Hydrogen (hydrogenation) - breaks double bond, adds two
hydrogen atomsAlkene + Hydrogen Alkane C3H6 + H2 C3H8
B. Halogen (halogenation) - breaks double bond, adds two halogen atoms
Alkene + Halogen Halogen substituted hydrocarbon C3H6 + Cl2 C3H6Cl2
The Alkynes - Unsaturated hydrocarbons
Characteristics unsaturated hydrocarbons (1 triple bond) homologous series (follow same pattern) fewer # of carbons - lower boiling points follow same general formula - CnH2n-2
end in -yne
The Alkynes
Ethyne (acetylene)H C C H C2H2
Propyne HH C C C H C3H4
H
1-Butyne H HH C C C C H C4H6
H H
2-Butyne H H H C C C C H C4H6
H H
Reactions of the Alkynes1. Combustion
Alkyne + Oxygen Carbon dioxide + Water
2. Addition A. Hydrogen (hydrogenation) - breaks triple bond, adds four
hydrogen atomsAlkyne + 2 Hydrogen Alkane C2H2 + 2 H2 C2H6
B. Halogen (halogenation) - breaks triple bond, adds four halogen atoms
Alkene + 2 Halogen Halogen substituted hydrocarbon C2H2 + 2 Cl2 C2H2Cl4
The Benzene Series (Aromatic hydrocarbons)
The benzene series consists of molecules which are cyclic in nature.The general formula is CnH2n-6.
Benzene HC
H C C HC6H6
H C C HCH
Although it appears that the structure has alternating double and single bonds, the bonding involves six identical bonds. A resonance structure is used to show structural formula of benzene.
H HC C
H C C H H C C H
H C C H H C C HC CH H
An abbreviated structural formula can be used in place of the above:
OR
Toluene or Methylbenzene C7H8
HC
H C C CH3
H C C HCH
An abbreviated structural formula can be used in place of the above:
CH3 CH3
The Functional GroupsThe Alcohols - Characteristics
Functional Group : -OH hydroxyl group General Formula : R-OH (R stands for a radical -
methyl, ethyl, propyl, etc.) Soluble in water (less than 5 C atoms) Non-electrolyte: 0% ionization Name ends in - ol
Monohydroxy Alcohols
Methanol H H C O H CH3OH
H
Ethanol H H H C C O H C2H5OH
H HProduced by FermentationGlucose zymase Carbon dioxide +
EthanolC6H12O6 CO2 + C2H5OH
1-propanol H H H H C C C OH C3H7OH
H H HThe above is a primary alcohol
2-propanol (isopropyl alcohol)H H H
H C C C H C3H7OHH OH H
The above is a secondary alcohol.The -OH is attached to a C atom which is attached to two others.
1-butanol H H H H H C C C C OH C4H9OH
H H H H
2-butanol H H H H H C C C C H C4H9OH
H H OH H
2-methyl-2-propanol (tertiary butanol)
H H C H H H H C C C H C4H9OH H OH H
Tertiary alcohol - the -OH is attached to a C atom which is attached to three others.
Di-hydroxy Alcohols - contain two -OH groups
OH OH H C C H C2H4(OH)2
H H
1,2-ethanediol (ethylene glycol)anti-freeze
Tri-hydroxy Alcohols - contain three -OH groupsH H H
H C C C H C3H5(OH)3
OH OH OH
1,2,3-propanetriol (glycerine or glycerol)
Saponification - production of soap from the reaction of fatty acid and a base.
Fatty acid + base soap + glycerine
C3H5(C17H35COO) 3 + 3 NaOH 3 C17H35COONa + C3H5(OH)3
Organic AcidsCharacteristics
contain carboxyl group: -COOH ionize weakly - poor electrolytes strong odor short chain compounds are soluble in water name ends in: -oic acid
Structural formula OC O H
Methanoic Acid O (Formic Acid) H C O H HCOOHEthanoic Acid H O(Acetic Acid) H C C O H CH3COOH
H
Propanoic Acid H H O H C C C O H C2H5COOH
H H
EstersCharacteristics
Functional group: -COO- General formula: R-COO-R’ Artificial odors End in -oate Formed from esterification reaction
Acid + alcohol ester + waterRCOOH + ROH RCOOR’ + H2O
Methanol + Acetic Acid Methyl ethanoate + water
CH3OH + CH3COOH CH3COOCH3 + H2OEthanol + Methanoic Acid Ethyl methanoate + water
C2H5OH + HCOOH HCOOC2H5 + H2ONaming of the esters:
1- Name the second R group2- Count the remaining C atoms - name as an alkane, dropping the e and adding -oate
KetonesCharacteristics
Functional group: -CO- General formula R-CO-R’ End in -one
Propanone (Acetone) H O H H C C C H CH3COCH3
H H
Butanone H H O H H C C C C H C2H5COCH3
H H H
AldehydesCharacteristics
Functional group: -CHO General formula: R-CHO End in: -al
Methanal (formaldehyde) HH C O HCHO
Ethanal H H H C C O CH3CHO
H
Ethers
Characteristics Functional group: -O- General formula: R-O-R’ End in: ether
Dimethyl ether H H H C O C HCH3OCH3
H H
Ethyl methyl ether H H H H C O C C H C2H5OCH3
H H H
Amines
Characteristics Functional group: N General formula: R N R”