Chapter 8 Lecture Basic Chemistry Fourth Edition Chapter

Chapter 8 Lecture Basic Chemistry Fourth Edition Chapter 8 Chemical Reactions 8. 4 Functional Groups and Reactions of Organic Compounds Learning Goal Classify organic molecules according to their functional groups; draw the condensed structural formulas for products of reactions of organic compounds. © 2014 Pearson Education, Inc. The propane from the torch undergoes combustion, which provides energy to solder metals.

Organic Reactions, Combustion The most common type of reaction that organic compounds undergo is combustion. Hydrocarbons are carbon-hydrogen compounds • used as fuels; gasoline is a mixture of different hydrocarbons • burned in the presence of oxygen to produce carbon dioxide, CO 2, water, and energy © 2014 Pearson Education, Inc.

Combustion of Alkanes Propane, a hydrocarbon with three carbon atoms, is used as fuel in portable heaters and barbeques. The balanced reaction for combustion of propane, C 3 H 8, is © 2014 Pearson Education, Inc.

Covalent Bonds in Organic Compounds © 2014 Pearson Education, Inc.

Functional Groups Organic compounds are organized according to their functional groups, specific groups of atoms that undergo characteristic chemical reactions. Compounds with the same functional group have similar chemical properties. © 2014 Pearson Education, Inc.

Functional Groups, Alkenes Organic compounds that contain carbon-carbon double bonds are called alkenes. The simplest alkene contains two carbons: ethene, In ethene, each carbon is attached to • a double bond • two hydrogen atoms, with single bonds © 2014 Pearson Education, Inc.

Functional Groups, Alkenes Ethene is a plant hormone that promotes the ripening of fruit such as bananas and avocados. © 2014 Pearson Education, Inc. Fruit that is picked early is ripened by exposure to ethene.

Chemistry Link to the Environment Many insects emit very small quantities of chemicals called pheromones to send messages to other members of the same species. Pheromones can be used • as a signal of danger • to mark a trail • to attract members of the opposite sex © 2014 Pearson Education, Inc.

Chemistry Link to the Environment One such communication chemical is called bombykol, emitted by female silkworm moths. Bombykol • attracts male silkworm moths • contains two double bonds and an alcohol group • can be made by scientists and used as a nontoxic pesticide © 2014 Pearson Education, Inc.

Chemistry Link to the Environment Bombykol attracts male silkworm moths. © 2014 Pearson Education,

Hydrogenation of Alkenes undergo • addition reactions, where atoms are added to each side of the double bond • hydrogenation reactions, where hydrogen atoms are added to each side of the double bond, turning the alkene into an alkane © 2014 Pearson Education, Inc.

Hydrogenation of Alkenes Hydrogenation reactions require a catalyst such as platinum (Pt), nickel (Ni),

Functional Groups, Aromatic Compounds In 1825, Michael Faraday isolated benzene, a hydrocarbon with the formula C 6 H 6. Because molecules that contain benzene often have fragrant odors, they are called aromatic compounds. Benzene is a six-carbon ring with alternating single and double bonds. © 2014 Pearson Education, Inc.

Functional Groups, Aromatic Compounds Benzene molecules are often represented by a hexagon with a circle in the center. One example of an aromatic compound, thymol, is found in thyme. © 2014 Pearson Education, Inc.

Functional Groups, Alcohols In an alcohol, a hydroxyl (—OH) group replaces a hydrogen in a hydrocarbon. Ethanol • has the formula • has been known since prehistoric times as an intoxicating product © 2014 Pearson Education, Inc.

Functional Groups, Alcohols Ethanol (ethyl alcohol), CH 3 CH 2 OH, is formed by the fermentation of grains, sugars, and starches. Ethanol is used as a solvent for perfumes, varnishes, and some medicines, such as tincture of iodine. © 2014 Pearson Education, Inc.

Combustion of Alcohols burn with oxygen to produce carbon dioxide and water. Desserts may be prepared by pouring liquor on fruit or ice cream and lighting it. © 2014 Pearson Education, Inc. A flaming dessert is prepared using a liquor containing ethanol that undergoes combustion.

Functional Groups, Aldehydes, and Ketones Aldehydes and ketones contain a carbonyl group (C O), which is a carbon atom attached to an oxygen atom with a double bond. • In an aldehyde, the carbon atom of the carbonyl group is also bonded to a hydrogen atom. • In a ketone, the carbon atom of the carbonyl group is bonded to two other carbon atoms. © 2014 Pearson Education, Inc.

Functional Groups, Aldehydes, and Ketones Aldehydes and ketones are often found in food flavorings such as vanilla, cinnamon, and spearmint. Formaldehyde, the simplest aldehyde, is a colorless gas with a pungent odor, used as a germicide and as a way to preserve biological specimens. © 2014 Pearson Education, Inc.

Functional Groups, Aldehydes, and Ketones The simplest ketone, known as acetone or propanone, is a liquid with a mild odor. It is widely used as a solvent in cleaning fluids, paint, and nail polish removers. In the body, acetone may be produced in uncontrollable diabetes, fasting, and with highprotein diets when large amounts of fats are metabolized for energy. © 2014 Pearson Education, Inc.

Functional Groups, Carboxylic Acids In a carboxylic acid, the functional group is the carboxyl

Functional Groups, Carboxylic Acids The functional group in the formula for a carboxylic acid can be drawn as follows: Acetic acid, CH 3−−COOH, and water form a solution called vinegar, used in food preparation. © 2014 Pearson Education, Inc.

Functional Groups, Esters are similar to carboxylic acids, except the hydrogen atom attached to the oxygen is replaced by a carbon atom. The functional group in an ester can be drawn as follows: or © 2014 Pearson Education, Inc. CH 3—COO—CH 3

Functional Groups, Esters Many fragrances found in perfumes and flowers are due to esters. Esters are also responsible for the odor and flavorings in oranges, bananas, pears, pineapples, and strawberries. © 2014 Pearson Education, Inc. Esters such as ethyl butanoate provide the odor and flavor of many fruits such as pineapples.

Chemistry Link to Health In the 1800 s, chemists discovered that salicin, found in willow tree bark, was responsible for the relief of pain. When ingested, the body converts salicin to salicylic acid, which irritates the stomach lining. The discovery of salicin in the leaves and bark of the willow tree led to the development of aspirin. © 2014 Pearson Education, Inc.

Chemistry Link to Health In 1899, the Bayer Chemical Company produced an ester of salicylic acid called acetylsalicylic acid (aspirin), which is less irritating to the stomach. © 2014 Pearson Education, Inc.

Functional Groups, Amines are derivatives of ammonia, NH 3, in which the nitrogen atom

Functional Groups, Amines are responsible for fish odor. As the proteins in fish decay, they produce putrescine and cadaverine, which have a particularly pungent and offensive odor. © 2014 Pearson Education, Inc.

Functional Groups, Amides In an amide, the hydroxyl group of a carboxylic acid is replaced by a nitrogen group. Compounds that contain amides are used to reduce fever and relieve pain. © 2014 Pearson Education, Inc.