Organic Reactions Aim OC 3 – What are the most common organic reactions?

Combustion Reactions –burning of hydrocarbons with oxygen –with sufficient oxygen, –carbon dioxide and water are produced C 3 H 8 + 5O 2  3CO 2 + 4H 2 O –with insufficient oxygen –carbon monoxide and water are produced 2C 3 H 8 + 7O 2  6CO + 8H 2 O Substitution Reactions –replacement of hydrogen by other compounds in saturated hydrocarbons –example: halogen substitution 2 CH 4 + F 2  2 CH 3 F + H 2 –name the substances in the following substitution rxn: 2 C 2 H 6 + Cl 2  2 C 2 H 5 Cl + HCl

Addition –Hydrogen or other atoms added at the broken double or triple bonds in unsaturated hydrocarbons –Halogenation Halogens (F, Cl, Br, etc.) added to carbons at a double or triple bond break 2 C 2 H 4 + F 2  2 C 2 H 4 F 2 ethene fluorine1,2 difluoroethane –Hydrogenation Hydrogen is added to carbon atoms at an alkene / alkyne bond break Example: 2 C 2 H 4 + H 2  2 C 2 H 6 ethene ethane

Fermentation enzymatic breakdown of organic molecules during anaerobic respiration enzymes contained in yeast cells cause reaction glucose  ethanol + carbon dioxide or C 6 H 12 O 6  2C 2 H 5 OH + 2CO 2 Used in wine / beer / alcohol production

Esterification –formation of esters; an alcohol and an acid are reacted in a dehydration synthesis reaction –importance: allows for the formation of fruit flavorings, aromas and fats –Example: ethyl benzoate (wintergreen odor)

Saponification –Soap making reaction; produces organic salts called soaps –Requires the hydrolysis (breakdown with water) of fats by bases –General formula

Polymerization –formation of large molecules from repeating units of smaller ones –Polymer - large molecule formed from many smaller, repeating units or monomers

Condensation polymerization –joining monomers by dehydration synthesis –H 2 O is removed and the monomers are attached Examples: –Silicones –Polyesters –polyamides (nylon) –and plastics

Addition polymerization –involves opening up double and triple bonds of unsaturated hydrocarbons –The carbons at each end of the monomer add the next monomer to it and form a chain or polymer Examples: –Vinyl plastics –Polyvinylchloride (PVC) –Polyethylene –Polystyrene

Petroleum Latin – “rock oil” A naturally occurring, yellow-to-black liquid found in sedimentary rock formations beneath the Earth's surface A fossil fuel (nonrenewable resource) A mixture of hydrocarbons of various molecular weights Methane makes up a large percentage of petroleum Commonly refined into various types of fuels

Fractional Distillation Distillation – the separation of various substances based on different boiling points Fractional distillation separates each fraction in the mixture based on the various components of crude oil by –different sizes –weights –boiling temperatures Done in oil refineries (think New Jersey near the Goethals Bridge…

Diagram of a Fractional Distillation Set up

Cracking The breakdown of larger, less valuable hydrocarbons by heat and pressure into smaller, more valuable ones like: –Gasoline –kerosene or jet fuel –lighter gases methane, ethane, etc.