Organic Chemistry In Life

University:
American Baptist College
Course:
CIT370 | Database Design and Processing
Academic year:

2019
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0

Pages:

31
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customer-7930190

CHEM 258 ORGANIC CHEMISTRY in LIFE CHAPTER 1 An introduction to organic chemistry: The power of hydrocarbons Carbon’s ability • Bond to as many as four other atoms simultaneously, • Form strong bonds to atoms of several other elements • Form molecules containing many and varied branches, as well as molecules composed of long, unbranched strings of carbons. Assoc. Prof.Öznur DEMİR ORDU Definition • Hydrocarbon, any of a class of organic chemical compounds composed only of the elements carbon (C) and hydrogen (H). Assoc. Prof.Öznur DEMİR ORDU • Nineteenth-century chemists classified hydrocarbons as either aliphatic or aromatic on the basis of their sources and properties. • Hydrocarbons are the principal constituents of petroleum and natural gas. They serve as fuels and lubricants as well as raw materials for the production of plastics, fibres, rubbers, solvents, explosives, and industrial chemicals. Assoc. Prof.Öznur DEMİR ORDU • Combustion reaction releases energy: used for heating, cooking and in industrial processes • Burning gasoline and diesel fuel: to run our cars, trucs and buses • Burning jet fuel: for our airplanes • Burning wood, coal and kerosene to heat our homes. Assoc. Prof.Öznur DEMİR ORDU Aliphatic hydrocarbons • Aliphatic hydrocarbons are divided into three main groups according to the types of bonds they contain: alkanes, alkenes, and alkynes. Alkanes have only single bonds, alkenes contain a carbon-carbon double bond, and alkynes contain a carbon-carbon triple bond. Assoc. Prof.Öznur DEMİR ORDU CLASSES of HYDROCARBONS • ALKANES: Saturated hydrocarbons (Straight and branched-chain isomers) • ALKENES hydrocarbons ALKANES Assoc. Prof.Öznur DEMİR ORDU and ALKYNES: Unsaturated REACTIVE COUSINS of Alkanes: properties and uses • Very low toxicity • Colorless and odorless • Methane, ethane, propane and butane: ignite very easily when mixed with air and either burn or explode Assoc. Prof.Öznur DEMİR ORDU Alkanes Assoc. Prof.Öznur DEMİR ORDU CH4, methane • The principal component of natural gas • Burning: produces not only CO2 and H2O, but light and heat as well. Assoc. Prof.Öznur DEMİR ORDU CH4, methane • Methane: the major component of the natural gas used for cooking and heating. • Mixtures of about 5 to 15% methane in air are highly explosive. • They are the dangerous firedamp that often forms in coal mines. Assoc. Prof.Öznur DEMİR ORDU CH4, methane • Because it is odorless, in order to dedect a small leak of natural gas, usually an organic compound of sulfur called mercaptan (methanethiol) (an odorizer ) is added to natural gas. • It gives the gas a strong odor Assoc. Prof.Öznur DEMİR ORDU Propane and butane • Propane and butane: Used as commercial fuel LPG (Liquefied petroleum gas). Assoc. Prof.Öznur DEMİR ORDU Other alkanes • Several of higher-molecular weight alkanes, begining with pentane, are liquids and are the major components of gasoline. • Larger alkanes are oily or greasy liquids or waxy solids (i.e.candle wax) at room temperature. Assoc. Prof.Öznur DEMİR ORDU Alkenes: properties and uses • Unlike alkanes, they have characteristic odors. • Little direct use to consumers Assoc. Prof.Öznur DEMİR ORDU ETHENE • ETHENE (or Ethylene): it is used in the production of polyethelene Assoc. Prof.Öznur DEMİR ORDU Ethylene in nature • Many fruits and vegetables, especially citrus fruit and tomatoes release ethylene as they ripen. This speeds further ripening. • Some fruit produce ethylene as ripening begins. Apples and pears are examples of fruit that produce ethylene with ripening. Ethylene is responsible for the changes in texture, softening, color, and other processes involved in ripening. Assoc. Prof.Öznur DEMİR ORDU RIPENING • Commercial growers sometimes use this phenomenon to accelerate the maturation of fruit and vegetables. • Ethylene gas is used commercially to ripen tomatoes, bananas, pears, and a few other fruits postharvest. Assoc. Prof.Öznur DEMİR ORDU RIPENING by ETHYLENE • Green tomatoes may be ripened by exposure to ethylene gas. Assoc. Prof.Öznur DEMİR ORDU RIPENING by ETHYLENE • Ethylene has been known to be harmful to vegetation— decreasing product quality and shelf-life. Assoc. Prof.Öznur DEMİR ORDU Alkynes: Acetylene (ethyne) • Acetylene has extensive commercial use, because it burns with a very hot flame. • It is important as the fuel of the oxyacetylene torch used in welding. Assoc. Prof.Öznur DEMİR ORDU THE CYCLIC HYDROCARBONS • Cycloalkanes: mainly used as solvents Assoc. Prof.Öznur DEMİR ORDU Aromatic compounds • Benzene and derivatives, used as solvents -Benzene: cancinogenic (cancer-causing):It causes a form of leukemia. Assoc. Prof.Öznur DEMİR ORDU • Toluene, also known as toluol, is a substituted aromatic hydrocarbon. • It is a colorless, water-insoluble liquid with the smell associated with paint thinners. It is used in some types of paint thinner, permanent markers, contact cement and certain types of glue Assoc. Prof.Öznur DEMİR ORDU • The xylenes are used in making dyes, insecticides and drugs. Assoc. Prof.Öznur DEMİR ORDU 2 or MORE BENZENE RING mothballs Assoc. Prof.Öznur DEMİR ORDU • Mothballs are classified as a pesticide and used to control moths, silverfish and other fiber pests in wool and other natural fiber clothing and materials. !!!! The chemicals in mothballs are toxic to humans and pets Assoc. Prof.Öznur DEMİR ORDU Found in charcoal smoke and cigarette smoke Assoc. Prof.Öznur DEMİR ORDU Both the smoke and the char on the meat contain polycyclic aromatic compounds Assoc. Prof.Öznur DEMİR ORDU The Greenhouse Effect • A greenhouse gas (sometimes abbreviated GHG) is a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range. This process is the fundamental cause of the greenhouse effect. • The primary greenhouse gases in the Earth's atmosphere are water vapor, carbon dioxide, methane, nitrous oxide, and ozone. Assoc. Prof.Öznur DEMİR ORDU • Burning of organic compounds (wood, coal, natural gas, petroleum and other fossil fuels):emmision of carbon dioxide. Assoc. Prof.Öznur DEMİR ORDU