Organic Reactions Hydrogenation Addition Substitution Combustion Esterification Fermentation Saponification Polymerization

Hydrogenation Unsaturated hydrocarbons undergo addition when H2 (g) is added: Note that hydrogenation produces a single product from two reactants: A + B  C

Addition Halogens (F2, Cl2, Br2, and I2) will combine with unsaturated hydrocarbons: Note that addition creates a single product from two reactants: A + B  C

Substitution Saturated hydrocarbons (alkanes) lose a hydrogen and gain a halogen: Note that there are two products in substitution reactions – addition only has one!

Distinguishing Between Addition and Substitution Table Q can help you with the identity of the hydrocarbon, which is usually representated as a chemical formula. Substitution Addition

Esterification Acid + Alcohol  Ester + Water Look for the functional groups to identify the reaction! R-OH + R-COOH  R-COOR + H2O A product or a reactant can be missing in a question

Combustion Organic Molecule + O2  CO2 + H2O Usually saturated hydrocarbons are used Balancing these equations is fun!

Fermentation Look for sugar reactant and alcohol and CO2 products:

Saponification Fat + OH-  Soap + Glycerol Only need to recognize the reaction! + NaOH(aq) 

Addition Polymerization Unsaturated hydrocarbon molecules are induced to add to each other, breaking double bonds.

Condensation Polymerization Esterification is the most common type of condensation reaction on the regents exam. Protein synthesis is a commonly cited example of condensation.

Review for Functional Group Test Organic compounds contain carbon atoms that are bonded to one another in chains, rings, and networks to form a variety of structures (polymers, oils, and other large molecules). Carbon has four valence electrons and always makes four covalent bonds with other atoms.

Functional groups impart distinctive physical and chemical properties to organic compounds. The functional groups contain electronegative elements (halogens, O, and N). The more polar compounds have higher melting and boiling points than their hydrocarbon counterparts.

Hydrogen “bonds” When the electronegative element is bonded to hydrogen, it is capable of making hydrogen bonds. These strong intermolecular forces lead to higher MP and BP, and lower vapor pressures than other functional groups that are bonded to carbon only.

Hydrocarbons, organic acids, alcohols, esters, amines, amides, and amino acids are categories of organic molecules that differ in their structural formulas as a result of different functional groups.

What you need to be able to do… You need to be able to use Tables P, Q and R with ease to get the organic questions. Identifying functional groups, naming compounds, recognizing saturated and unsaturated hydrocarbons, especially in reactions; these are skills you need to have.

What You Will See Note that you will see full structural formulas and condensed structural formulas. Table R has partially condensed formulas. You need to be able to discern between these different ways of describing molecules.

IUPAC Organic Nomenclature System Hydrocarbons, organic acids, alcohols, and esters are names using the IUPAC system. The IUPAC system provides a method of distinguishing among isomers of organic compounds.

Isomers Isomers have the same molecular formula, empirical formula, and % composition. They test this definition a lot. If you’re not sure about an isomer, count the carbons, hydrogens, and oxygens; make sure they’re the same as the molecule in question.

Unsaturated organic compounds contain at least one double or triple bond. Each bond is a pair of shared electrons. How many electrons (or pairs) in double and triple bonds?

Recognizing Hydrocarbons You need to be able to recognize a alkane, alkene, or an alkyne by its chemical formula (Table Q). Know how to use the general formulas, and know. They often ask this question as part of a substitution or addition reaction question.

Addition, hydrogenation, substitution, polymerization, esterification, fermentation, saponification, oxidation, and combustion are examples of organic reactions. Addition is probably the most popular reaction they test with, followed by esterification.

List of Organic Reactions substitution (by halogens) of saturated hydrocarbons addition (by hydrogen and halogens) of unsaturated hydrocarbons esterification (condensation): alcohol + organic acid  ester + H2O combustion: organic compound + O2  CO2 + H2O fermentation: C6H12O6 (glucose)  2CH3CH2OH (ethanol) + 2 CO2 saponification: fatty acids + base  soap + glycerol addition polymerization: usually polyethylene (ethene) condensation polymerization: esters, proteins, polysaccharides, fats, synthetics