Organic Chemistry Carbon is a tramp - video Organic Chemistry A. Carbon Compounds organic compounds are those in which carbon atoms are almost always bonded to each other, to hydrogen atoms and a few other atoms (O, N, S, P) inorganic exceptions are the oxides of carbon, carbonates, cyanides and carbides (no C-C bonds or C-H bonds) eg) CO2, CaCO3, NaCN, SiC there are millions of organic compounds and all contain covalent bonds carbon is unique for two reasons: a) it can bond with other carbon atoms to form long chains, rings, spheres, tubes, sheets etc. b) it can form combinations of single, double and triple bonds (no other element does this!!!!) Practice question recall polarity and intermolecular forces from the chemical bonding unit polar bonds are formed when there is an uneven pull on e polar compounds are formed when the polar bonds within a molecule do not cancel each other out the presence of dipole-dipole forces and hydrogen bonding will allow polar compounds to dissolve in water, since it is also polar non-polar compounds only have LD forces between molecules and will not dissolve in water B. Structural Isomers isomers are compounds with the same molecular formula but a different structure Example 1 Draw the three structural isomers for C5H12. 1. H H H H H H C C C C C H H H H H 3. H 2. H H H CH3 H C C H C H3 H C H H H H C C C C H CH3 H H H H Example 2 Draw three structural isomers for C4H8F2 . 1. H H H H F C C C C H H 2. H H H F 3. H H H H F C C C C H F H H H H H F C C C C H H F H H H different structures result in different properties the arrangement of the atoms determines the types of intermolecular attractions which then determines properties such as boiling point and solubility in water Example Draw two isomers of C3H8O. Which one would have a boiling point of 7.4C and which would have a boiling point of 82.5C? Explain why the boiling points are so different. H H H H C C C H OH H H H 82.5C – has HB between molecules which makes the boiling point quite high H C H O H H C C H H H 7.4C – does not have HB between molecules therefore the boiling point is significantly lower Practice Question C. Formulas and Structural Diagrams organic molecules can be drawn in three different ways: 1. complete structural diagram – shows all bonds eg) C3H8 H H H H eg) C C C H H H C3H7F H H H H H C C C H H H F 2. condensed structural diagrams – shows carbon to carbon bonds but includes the hydrogens etc. attached to each carbon eg) C3H8 eg) C3H7F CH3 CH2 CH3 CH3 CH2 CH2F 3. line structural diagrams – shows only carbon bonds eg) C3H8 eg) C5H12 eg) C4H8 carbon to D. Prefixes 1. Number of Functional Groups 6 = hexa 2 = di 7 = hepta 3 = tri 8 = octa 4 = tetra 9 = nona 5 = penta 10 = deca 2. Number of Carbons 1 = meth 6 = hex 2 = eth 7 = hept 3 = prop 8 = oct 4 = but 9 = non 5 = pent 10 = dec E. Alkanes CnH2n+2 eg) C5H12, C20H42, etc. hydrocarbons containing only single bonds ie) they are can be long ring SATURATED continuous chains, branched chains, structures (cycloalkanes) 1. Properties nonpolar not soluble in water can be solid, liquid or gas depending on number of carbon atoms relatively unreactive because the single bonds are very stable 2. Uses natural gas, BBQ’s, lighter fluid, gasoline etc good for making plastics, lubricants 3. Naming IUPAC = International Union of Pure and Applied Chemistry i. Continuous Chains prefix + “ANE” (suffix) eg) H H H H H C C C C H H H H H butane ii. Branched Chains branches are called alkyl functional group 1 C = methyl ; 2C = ethyl ; 3 C = propyl etc find the longest carbon chain and number it so the branches get the lowest possible numbers to name: name the groups first (in alphabetical order), including the number of the carbon where each group is found, then name the longest chain (parent name) H eg) H H H H 1 2 3 4 5 H C C C C C H H CH3 H H 3-methylpentane H methyl H H 1 C H H 2 C H 3 C H 4 C H 5 C CH3 CH2 H H methyl CH3 ethyl H 3-ethyl-2-methylpentane Step #1 – find the longest parent chain Step #2 – draw a square around the branches Step #3 – give numbers to the chain: make sure the branches get the smallest number possible H H H H H H 1 2 3 4 5 C C C C C H H CH3 H H H 3 – methyl pentane eg) H H H H H 5 4 3 2 1 H C C C C C H H H CH3 CH3 H methyl methyl 2,3-dimethylpentane iii. Cycloalkanes use the ring structure as the “parent” “cyclo”+ prefix + ANE eg) cyclobutane cyclopropane name if there are branches, number the carbons in the ring so the branches get the sequence lowest possible number eg) 5 4 3 1 2 CH2 CH3 ethyl CH3 methyl 1-ethyl-3-methylcyclopentane Practice Questions F. Alkenes CnH2n eg) C5H10, C20H40, etc. hydrocarbons containing one or more double bonds ie) they are UNSATURATED can be long continuous chains, branched chains, ring structures (cycloalkenes) 1. Properties nonpolar not soluble in water lower boiling point than corresponding alkane because they have fewer e which makes the LD forces of attraction weaker eg) ethane BP = 88.6C more reactive ethene BP = 103.8C than alkanes double bond has more e- in the same area greater repulsion and bond less stable diagnostic test: use KMnO4(aq) or Br2(l) Show video ***alkenes (double bond) will react with these substances causing a noticeable colour change, alkanes will not Br2(l) A alkene B KMnO4(l) alkane A alkane B alkene *** the alkenes will react causing the colour to disappear as the coloured substance is used up in the reaction 2. Uses plastics (PVC) steroids welding torches 3. Naming i. Continuous Chains prefix + “ENE” (suffix) number carbons to give the double bond the lowest number the number where the double bond starts is to be given as a “ # ” between the prefix and the suffix eg) H H H H H H C C C‗ C C C H H H hex-3-ene H H H H H H H H ‗ H C C C C C H H H H H H H H C H pent-2-ene ‗ C C C H H H but-1-ene ii. Branched Chains find the longest carbon chain and number it so the double bond gets the lowest possible number to name: name the groups first (in alphabetical order), including the number of the carbon where each is found, then the parent name including the number of the carbon where the double bond starts eg) CH2‗ C CH2 CH2 CH2 CH2 CH3 CH2 2-ethylhept-1-ene CH3 CH3 CH ‗ CH CH CH CH CH3 CH3 CH3 CH2 CH2 CH3 4,5,6-trimethylnon-2-ene iii. Cycloalkenes double bond is always numbered 1, 2 branches get the lowest numbering sequence after the double bond “cyclo”+ prefix + ENE list branches in alphabetical order with the number of the carbon they are on cyclohexene eg) cyclopropene 2 CH2 CH3 3 3-ethylcyclobutene 1 4 CH3 1 4 2 3 CH3 CH2 CH3 3-ethyl-1,3-dimethylcyclobutene G. Alkynes CnH2n-2 eg) C5H8, C20H38, etc. hydrocarbons containing one or more triple bonds ie) they are also UNSATURATED can be long continuous chains, branched chains not plentiful in nature 1. Properties nonpolar very reactive (more than alkanes and alkenes) triple bond has 6 e- in the same area high force of repulsion boiling points are higher than corresponding alkanes and alkenes because of their linear structure and the nature of triple bonds 2. Uses welding torches 3. Naming i. Continuous Chains prefix + “YNE” number carbons to give the triple bond the lowest number the number where the triple bond starts is to be given as a “ # ” between the prefix and the suffix eg) H H H C C H H H H H C≡ C C C hex-3-yne H H H H H C C≡ C C C H H H H H pent-2-yne ii. Branched Chains find the longest carbon chain and number it so the triple bond to name: gets the lowest number name the groups first (in alphabetical order), including the number of the carbon where each is found, then the parent name including the number of the carbon where the triple bond starts eg) CH≡ C CH CH2 CH2 CH2 CH2 CH3 CH2 CH2 CH3 3-propyloct-1-yne CH3 CH CH3 C≡ C CH CH CH3 CH3 CH2 CH3 2,5,6-trimethyloct-3-yne Review alkanes – branches, rings – least reactive alkenes – branches, rings alkynes – branches – most reactive all called aliphatics all nonpolar and not soluble in water major intermolecular forces are LD boiling points are low Video Practice Question Practice Question H. Aromatics hydrocarbons containing one or more Video benzene rings C6H6 OR all bonds are the same length and strength we draw benzene like this: 1. Properties nonpolar the benzene ring structure is very stable aromatics are characterized by strong aromas 2. Uses ASA, amphetamines, adrenaline, benzocaine (anesthetic) moth balls, TNT wintergreen, menthol, vanilla, cinnamon SPF in sunscreen 3. Naming i. Benzene as a Branch if you have a really long carbon chain, it is easier to call the benzene ring a “phenyl” group eg) 4-phenylheptane CH3 CH2 CH2 CH CH2 CH2 CH3 ‗ CH2 CH CH CH2 C CH2 CH2 CH3 CH3 3-methyl-5,5-diphenyloct-1-ene ii. Benzene as a the Main Compound if only one group is attached, give the alkyl name attached to “benzene” (no number is necessary) eg) CH3 methylbenzene if there is more than one branch, number them so they get the lowest sequence alphabetically and name CH3 eg) 1-ethyl-3-methylbenzene CH2 CH3 CH3 1,3-dimethyl-5-propylbenzene CH3 CH3 CH2 CH2 C2H5 CH3 1-ethyl-3-methylcyclohexane ***Watch out for this!!! http://www.bing.com/videos/search?q=benzene&mid=013F6F84DA6614E381A6013F6F84DA6614 E381A6&FORM=LKVR4# Practice Question I. Alcohols R - OH organic compounds with one or more OH (hydroxyl) groups ** OH, its an Alcohol!!! 1. Properties have much higher boiling points corresponding aliphatics because of bonding! eg) methane (CH4) BP = -162C methanol (CH3OH) BP = 65C than hydrogen polar the –OH end of the alcohol is polar while the carbon chain end is not small alcohols are soluble in water and large alcohols are not 2. Uses antifreeze, rubbing alcohol, beverages, moistening agent 3. Naming number the longest carbon chain containing the hydroxyl group so the –OH group gets the lowest number aliphatic name (without “e” at end) + “OL” give the number for the carbon where the –OH group is found between the parent name and the suffix if there is more than one hydroxyl group, use a prefix ( di, tri, tetra ) to indicate the number of OH groups and place the numbers between the parent name and the suffix ***Note, if the suffix starts with a vowel, drop the “e” on the parent name; if the suffix starts with a consonant, keep the “e” on the parent name eg) H H H H H H H C C C C H H OH H CH3 H H C C C C H H OH H H H butan-2-ol 3-methylbutan-2-ol H H CH3 H H C C C H OH OH H C H 2-methylbutane-2,3-diol an unusual case: OH phenol J. Organic Halides R-X where R is carbon chain or ring and X is a halogen organic compounds where hydrogen has been replaced by one or more halogens (F, Cl, Br, I) do not readily occur in nature 1. Properties can be polar or nonpolar , depending on the placement of the halogen groups many are toxic and dangerous 2. Uses manufactured for human use eg) DDT, PCB, CFC anesthetics dry cleaning fluid plastics, polymers (Teflon) 3. Naming same rules as before… name branches ( halogens included now) alphabetically F = fluoro Cl = chloro eg ) H H Cl Cl H C C C C H H H H H Br = bromo I = iodo 2,3-dichlorobutane I 2-fluoro-4-iodo-1-methylbenzene CH3 F K. Carboxylic Acids R O ║ C OH where R is carbon chain or ring organic compounds containing the carboxyl functional group (-COOH) ** o – oh, its an acid!!! – mnemonic device 1. Properties polar dissolve in water high boiling points due to hydrogen bonding weakly acidic diagnostic test: use litmus paper (will turn red ), readily react with metals, neutralize bases 2. Uses recycling rubber – methanoic acid vinegar – ethanoic (acetic) acid rust remover – oxalic acid fruits – citric acid 3. Naming count the longest carbon chain including the carbon in the carboxyl group the carbon in the carboxyl group is always number 1 drop “e” and add “OIC ACID” eg) O methanoic acid ║ H C H H C H OH O ║ C OH ethanoic acid O ║ C I OH H H H C C C H H H benzoic acid O ║ C OH 4-iodobutanoic acid Read pg 438 - 441 Read pg 438 – 441 on esters L. Esters R O ║ C O R’ where R can be a carbon chain or hydrogen and R’ can be a carbon chain combination of a carboxylic acid and an Alcohol ** Ester is a cow that likes to eat OATES 1. Properties polar small esters dissolve in water, large esters do not boiling points slightly lower than corresponding carboxylic acids and alcohols due to lack of hydrogen bonding very volatile which allows them to generate aromas 2. Uses flavouring agents 3. Naming identify the alcohol used to make the ester change the alcohol name to the corresponding alkyl name eg) methanol would become methyl identify the made from carboxylic acid the ester was drop the “oic acid” and replace with “oate” eg) butanoic acid would become “butanoate” put the two names together with a space in between eg) methyl butanoate you can have branches on esters…they follow the alphabetical rule, numbering begins at the O end of the alcohol and the C=O end of the carboxylic acid eg) H H H H C C C H H H H H H C C H H O H H ║ C O C C H H H ethyl butanoate O H CH3 ║ C O C C H H H propyl propanoate eg) Video O ║ H H H C C C CH3CH3 H H O C C H H H ethyl 2-methylbutanoate Practice Question Practice Questions Practice Questions M. Boiling Points and Solubility we can compare the boiling points of various organic compounds using their polarity and the intermolecular attractions between the molecules Example 1 Put the following organic compounds in order from highest boiling point to lowest boiling point. alcohol, alkane, alkene, aromatic, carboxylic acid carboxylic acid alcohol aromatic alkane alkene highest lowest Example 2 Put the following homologous series of organic compounds in order from highest boiling point to lowest boiling point. C2H6, C2H5OH, CH3COOH, C2H4 CH3COOH C2H5OH highest C2H6 C2H4 lowest we can also compare the solubility of various organic compounds using their polarity Insoluble Organic Compounds Soluble Organic Compounds aliphatics – alkanes, alkenes, alkynes carboxylic acids aromatics alcohols – large (7 or more carbons) alcohols – small (less than 7 carbons) esters – large esters – small organic halides organic halides Practice Question N. Organic Reactions 1. Combustion Reactions occurs when a hydrocarbon reacts with oxygen products are always carbon dioxide and water these are economically important reactions for they are the major reactions that produce thermal energy required for fuelling our vehicles, heating our homes, and producing electricity eg) 1 C5H12(l) + 8 O2(g) 5 CO2(g) + 6H O 2 (g) eg) 1 C5H12(l) + 8 O2(g) 5 CO2(g) + 6 H2O(g) H H H H H C C C C H H H H H + 6.5 O2(g) 4 CO2(g) + 5 H2O(g) ***balance these reactions 2. Addition Reactions a double or triple bond in an alkene or alkyne is broken and a group or element is added (a catalyst is present) eg) H H C H ‗ C + H Cl Cl Cl H H C C Cl H H H H C ‗ C + H H H H C H ‗ C OH H H C C OH H + H H H H H H H H H C C H H H H C H ‗ C + H Br H H H H C C Br H H H H H C≡ C H + 1 Cl2 H C ‗ C Cl Cl Cl Cl H C≡ C H + 2 Cl2 H C C Cl Cl H 3. Substitution Reactions the replacement ( substitution ) of a hydrogen on an alkane or aromatic with another atom (eg. F, Cl etc) commonly used to make organic halides Examples 1. H H C H H H + cat Cl – Cl H C Cl H + H - Cl 2. + Br – Br 3. + Br cat + cat I–I + H - Br H-I I 4. H H H H H C C C C H H H H H + Br2 cat H H Br H H C C C C H H H H H + H - Br Practice Question 4. Esterification Reactions the reaction of a carboxylic acid with an alcohol the catalyst is sulphuric acid Catalyst video Examples 1. H O ║ C H OH + HO C H H2SO4(aq) H H O ║ C H O C H H + H – OH 2. H H H C C H H O ║ C H H OH + HO C C H H H H H C C H H O ║ C H2SO4(aq) H O H H C C H H H + H – OH 5. Elimination Reactions an alcohol has water removed, forming an alkene plus the water organic halides can react with a base (hydroxide) to produce an alkene , a halide ion and water Examples 1. H H H C C H H OH cat H H H C‗ C H + H – OH 2. H 3. H H H H H C C C C OH H H H H H C C H H Cl cat H + OH H C ‗ H H H C C C H H H cat H H H + H – OH H – OH + Cl H C‗ C H + 6. Polymerization Reactions a monomer is a simple molecule the base unit for a polymer that forms a polymer is a very, very long molecule formed by the covalent bonding of monomers depending on the polymer, the monomers that make it up can be the same or different bazillions of polymers can be natural eg) carbohydrates, proteins, DNA polymers can be synthetic eg) nylon, PVC, Teflon, polyester polymers that can be heated and molded into specific shapes are commonly called plastics plastics are one type of synthetic compound that has been of great benefit to society (although there are also problems associated with then) the names of polymers are the monomer name with “poly” in front many have classical names instead of IUPAC names Addition Polymers formed when the electrons in double or triple bonds in the monomer units are rearranged the polymer is the only product formed Examples 1. H H ‗ C C H H ‗ + H H C C H H cat … H H H H C C C C H H H H polyethene … n 2. F F ‗ C C F F ‗ + F F C C F cat … F F F F F C C C C F F F F … n Teflon 3. H Cl ‗ C C H H ‗ C C + H Cl H cat … H H Cl H Cl C C C C H H H H … n polyvinyl chloride (PVC) 4. H H ‗ C C H ‗ + H cat … C C H H H H C C C C H H H H … n polystyrene (styrofoam) Practice Question Condensation Polymers polymerization reactions that involve the formation of a small molecule (commonly water ) as well as the polymer each monomer must have two functional groups two common linkages formed: 1. ester linkage – between carboxyl group (COOH) and hydroxyl group (OH) 2. amide linkage – between amino group (NH2) and carboxyl group (COOH) Examples 1. O ║ HO C O ║ C H H OH + HO C C H H ∙∙∙ O ║ O C OH cat ester linkage O H H ║ C O C C H H ∙∙∙ + H2O n polyethylene terephthalate PET 2. HO O H H ║ C C N H + HO H O H H ║ C C N H H ∙∙∙ cat amide linkage O H H O H H ║ ║ C C N C C N H H protein ∙∙∙ + H2O n Organic Chemistry Song O. Petroleum Refining Alberta has vast reserves of petroleum in the form of natural gas, crude oil and oil sand deposits most of this petroleum is refined and then burned as fuel petrochemicals are also used in the production of plastics refining of petroleum separates the crude mixture into purified components fractional distillation is used to separate the components distillation works because of the different boiling points of the components of crude oil the molecule and the lower the boiling point, the higher it rises in the tower (asphalt, fuel oil, wax at bottom; gasoline at top) the lighter distillation tower: Video Fractional Distillation 1. http://www.learnalberta.ca/content/t4tes/courses/senior/chemistry_30/mm/ m5/Fractional/main.html http://resources.schoolscience.co.uk/spe/knowl/4/flash/cracking.htm (animation of fractioning tower and cracking) 2. Animated tour http://sciencenetlinks.com/interactives/energy/interactive/api_treat_01281 0.swf 3. Animated tour - http://irvingoil.com/resource/flash/RefineryTour.swf Fractioning Tower two types of reactions in petroleum refining: 1. Cracking breaks long chain hydrocarbons into smaller units cracking requires heat and pressure there are many different types of cracking reactions, forming different products (alkanes, alkenes) eg) catalytic cracking, steam cracking, hydrocracking hydrocracking requires H2(g) Examples 1. C17H36 + cat H2(g) C9H20 + C 8H18 2. CH3 CH2 CH2 CH2 cat CH3 CH2 CH2 + H2(g) CH3 CH2 CH2 CH3 + CH3 CH2 CH3 2. Reforming small hydrocarbons are joined to make larger molecules requires heat and pressure there are several types of reforming reactions eg) alkylation to produce “high octane” gasoline all reforming reactions produce H2(g) Example C7H16 + C12H26 C 19H 40 + H2 Examples 1. C7H16 + C12H26 C 19H 40 + H2 2. ethane + octane decane + hydrogen gas Extraction of Bitumen in Oil sands lab http://www.learnalberta.ca/content/t4tes/cours es/senior/chemistry_30/mm/m5/c30_m5_l05_ mm006/c30_m5_l05_mm006.html Best song in the world Family song