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Organic Chemistry. P 267. Hydrocarbon. Hydro: hydrogen Carbon Additional element: Nitrogen, Oxygen, Sulphur Atomic number of carbon = 6 Valence electrons of carbon = 4 Each carbon atom has 4 bond in compound Ex: alkanes
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Organic Chemistry P 267
Hydrocarbon • Hydro: hydrogen • Carbon • Additional element: Nitrogen, Oxygen, Sulphur Atomic number of carbon = 6 Valence electrons of carbon = 4 Each carbon atom has 4 bond in compound Ex: alkanes Alkanes: hydrocarbon that consist of hydrogen and carbon, (single bond)
CH4, methane C2H6, ethane C3H8, propane C4H10, butane C5H12, pentane
C6H14, hexane C7H16, heptane C8H18, octane C9H20, nonane C10H22, decane
Structure Types of Propane Stick and ball model Displayed Formula 3 dimensional Formula H H Structural Formula H H CH3CH2CH3 H H H H Molecular Formula Skeletal Formula C3H8
ALCOHOL (-OH) PROPANE PROPANOL
ALCANOIC ACID BUTANOIC ACID BUTANE
ALDEHID/ALCANAL PENTANAL PENTANE
Ketones Butan-2-one
Alkylamine R-NH2 CH3CH2CH2NH2 Propylamine
ESTHER (Alkyl Alkanoate) propanoate methyl
Hydrocarbon with Branch 6 5 4 3 2 1 -Find the longest carbon chain, give the name - Find branch and give the name to the Branch: Carbon:Alkyl; 1 C atom: methyl 2 C atom: ethyl 3 C atom: propyl Halogen: F(Floro), Cl(Chloro), Br(Bromo), I(Iodo) - Give the number, branch number is the smallest number Same branch: 2 branchs: di 3 branchs: tri 4 branchs: tetra Hexane 2- Methyl
the branches names arranged alphabetically 3-bromo 9-chloro 4-methyldecan-3-ol
Alcanal, and alcanoic numbering begin from C attached to the function 5 4 3 2 1 4- methyl Pentanal
4 6 1 2 3 5 7 8 9 • Same branch: • 2 branchs: di • 3 branchs: tri • 4 branchs: tetra 4,6 -diethyl 2,4,7 -trimethyl nonane
Alcanal, and alcanoic numbering begin from C attached to the function 6-ethyl 3-floro 4,7-dimethyl octanoic acid Remember that the branches names arranged alphabetically
Task • Copy the table 15.2 page 270 in to your book
Determination of element mass in compound Compound: AmBn Mass of element A = Mass of element B = Find mass of carbon in 88 gr CO2 Mass of carbon = = = 24 gr
Determination of empirical formulae of organic compound 100,00 g amino acid(CpHqOrNs) react with oxygen and produced 117,10 g of carbon dioxide and 59,92 g of water. In kjeldahl a second of amino acid produced 22,64 g ammonia, determine the empirical formula of amino acid Answer - write the information mass of amino acid = 100 gr mass of carbon dioxide (CO2) = 117,10 gr mass of water(H2O)= 59,92 g mass of ammonia (NH3) = 22,64
Find mass of carbon in carbon dioxide = 31,94 g • Find mass of hydrogen in water = 6,66 g • Find mass of nitrogen in ammonia = 18,64 g • Find mass of oxygen in amino acid =mass of amino acid – carbon mass – hydrogen mass - nitrogen mass = 100 – 31,94 – 6,66 – 18,64 = 42,76 gr
Compare mass of the elements C : H : O : N 31,94 : 6,66 : 42,7 : 18,64 • Compare mol of the elements 31,94/12 : 6,66/1 : 42,76/16 : 18,64/14 2,67 : 6,66 : 2,67 : 1,33 • Divide by the smallest mole 2 : 5 : 2 : 1 • Determine the empirical formula C2H5O2N
Reactions Subtitution H H H H H C C Br + OH- H OH + Br- C C H H H H
Addition Double bondsingle bond Triple bonddouble or single bond Elimination single bondDouble bond double Triple bond + H2O H H H H H H H H C C C C H H OH OH C C C C H H H H H H H H H2O +
Hydrolysis Reaction involve breaking covalent bonds by reaction with water H H H H H C C Br + H2O H OH + HBr C C H H H H
Breaking Bonds in Different Ways Homolytic fission Each atom break to free radical (atom with unpaired electron + Heterolytic fission Each atom break to ion (cation and anion) - + +
Another example Homolytic fission CH3Br CH3+ Br Heterolytic fission CH3Br CH3++ Br- + Carbocation
Cycloalkane cyclohexane cyclobutane cyclopentane cyclopropane Methyl cyclohexane
Alkylamine (R-NH2) CH3NH2 methylamine CH3CH2NH2 ethylamine CH3CH2CH2NH2 propylamine
Alkenes C=C ethene CH2=CH2 CH2=CH-CH3 CH2=CH-CH2-CH3 CH2=CH-CH2-CH2-CH3 CH3-CH=CH-CH2-CH3 Double bond number is the smallest number in the longest carbon chain propene butene pentene pent-2-ene
Isomerism Structural isomer Different structural formula same molecular formula CH3-CH2-CH2-CH3 Butane, C4H10 Methyl propane, C4H10
Functional isomerism • Alcohol and eter • Ethanol: CH3-CH2-OH, molecular formula: C2H6O • Ether : CH3-O-CH3, molecular formula: C2H6O • Aldehid and ketones • pentanal: ,molecular formula:C5H10O • Penta-2-one C5H10O • Alkanoic acid and esthers • Propanoic acid • Methyl ethanoate Prove it !
Stereo isomer Geometric isomer (cis-trans isomerism) But-2ene: CH3-CH=CH-CH3 Cis-but-2-ene trans-but-2-ene
The star sign indicate chiral center. Chiral center is the carbon atom which carries four different groups Optical isomerism use 3 dimensional formula Occurs in the chiral molecules Butan-2-ol
Reactions Routes Write the reactions routes to convert: • Propene to propanol • pass propene and steam over heated phosphoric acid catalyst under pressure b. Propene to propanal • pass propene and steam over heated phosphoric acid catalyst under pressure untillpropanol forms • Distill on propanol to acidified potassium dichromate
Draw the structure of 5,7 dibromo, 2,6 dimethyl octan-3-one Solution steps Draw the longest chain Give the number Put the function Put the branches C O 1 2 3 4 5 6 7 8 C-C-C-C-C-C-C-C C Br Br