Presentation on theme: "Organic Chemistry The study of carbon based compounds with some exceptions. The exceptions are carbides, carbonates and oxides."— Presentation transcript:
Organic Chemistry The study of carbon based compounds with some exceptions. The exceptions are carbides, carbonates and oxides.
Why is the carbon atom unique? Carbon is unique It has 4 electrons in its outer shell. It has room for 4 bonds to 4 other atoms. These bonds can be single, double, or triple.
Hydrocarbons The largest group of organic compounds are known as hydrocarbons. These compounds contain hydrogen and carbon. Most of these compounds are derived from petroleum.
Petroleum Petroleum is a mixture of alkanes, cycloalkanes, and aromatic hydrocarbons. Petroleum is formed from the slow decomposition of buried marine life, primarily plankton and algae. As petroleum is formed it is forced through porous rock until it reaches an impervious layer of rock. Here it forms an accumulation of petroleum and saturates the porous rock creating an oil field.
Refinery and tank storage facilities, like this one in Texas, are needed to change the hydrocarbons of crude oil to many different petroleum products.
Hydrocarbons Hydrocarbons exist in three general shapes. Aliphatic- in chains
Hydrocarbons Cyclic- in rings
Hydrocarbons Aromatic – contain the benzene ring. They usually have distinctive odors.
Hydrocarbons Hydrocarbons are also distinguished by the type of bonds they contain between the carbon atoms.
Hydrocarbons based on bond type Alkanes – contain only single covalent bonds between carbon atoms. Alkenes – contain at least one double bond between carbon atoms. Alkynes – contain at least one triple bond between carbon atoms.
Alkanes, Alkenes, and Alkynes Carbon requires an octet. Carbon must have 4 bonds around it.
Alkane Nomenclature When writing the names for alkanes, prefixes must be known. The prefixes identify the number of carbon atoms in the compound. 1 methane CH 4 2 ethane C 2 H 6 3 propane C 3 H 8 4 butane C 4 H 10
Alkane Nomenclature 5 pentane C 5 H 12 6 hexane C 6 H 14 7 heptane C 7 H 16 8 octane C 8 H 18 9 nonane C 9 H decane C 10 H 22
Alkane Nomenclature When writing formulas for the alkanes we use the formula C n H 2n + 2 n represents the number of carbon atoms Example: methane contains 1 carbon atom. C 1 H 2 X CH 4 Without looking back at the prefixes write the molecular and structural formulas for ethane – butane.
Alkane practice 2 ethane C 2 H 6 3 propane C 3 H 8 4 butane C 4 H 10
Using the condensed method In the condensed form of a structural formula, carbon atoms are still written separately. However, the hydrogen atoms that are attached to a carbon atom are grouped with that carbon atom. Example: pentane C 5 H 12 H 3 C-CH 2 -CH 2 -CH 2 -CH 3 Write the molecular, traditional structural, and condensed structural formulas for octane.
Alkenes Alkenes must contain at least one double bond. They take the general form of C n H 2n. The first Alkene is ethene. C 2 H 4 Write the molecular formula and the structural formula for propene.
Alkenes that contain more than 3 carbon atoms When writing the names for alkenes that contain more than 3 carbon atoms the location of the double bond must be included. Example: Butene can be 1-butene or 2-butene. C 4 H 8 H 2 C=CH-CH 2 -CH 3 1-butene H 3 C-CH=CH-CH 3 2-butene
Determining the location of the double bond Carbon atoms are numbered by starting with the carbon atom closest to the double bond. The numbering can start from either side. H 2 C=CH-CH 2 -CH 3 1-butene
Determining the location of the double bond H 3 C-CH 2 -CH=CH 2 1-butene C 4 H Write molecular and structural formulas for 1-pentene 2-pentene 3-hexene
Alkynes Alkynes must contain at least one triple covalent bond. They take the general form of C n H 2n-2. The first alkyne is ethyne. Ethyne C 2 H 2 is also known as acetylene, which is used as the gas for welding.
Alkynes Alkynes use the same nomenclature as the Alkenes. After propyne the location of the triple bond must be identified. Write molecular and structural formulas for propyne, 2-butyne, 1-pentyne, and 3-heptyne.
Review of part I of an introduction to Organic chemistry Write molecular and structural formulas for the following (you may use the traditional or condensed structural formulas). 1. Methane 2. Propane 3. Ethene 4. 1-Butene 5. 2-Hexene 6. 3-Octene 7. Ethyne 8. 2-Heptyne 9. 3-Octyne
Hydrocarbon Radicals If one of the hydrogen atoms together with its associated electron is removed from a hydrocarbon molecule a radical is formed. Examples: Methane CH 4 becomes Methyl CH 3 Ethane C 2 H 6 becomes Ethyl C 2 H 5 Propane C 3 H 8 becomes_______________
Functional Groups A group of atoms that give characteristics and properties to organic compounds. These functional groups may be aldehydes, alcohols, ethers, ketones, amino acids, amides, and others. We will study the alcohols because of their wide use in combustion reactions.
Alcohols Alcohols contain the hydroxyl group OH. Unlike the hydroxide ion the hydroxyl group does not contain an electrical charge. Simple alcohols take the general form R - OH. The R represents a hydrocarbon radical. Symbol R An atom or a group of atoms with at least one unpaired electron. Example: If the radical is methyl (CH 3 ), the alcohol becomes CH 3 OH which is known as methyl alcohol or methanol. Write the molecular formulas for propyl alcohol and butanol.
Saturated and Unsaturated Hydrocarbons Saturated hydrocarbons contain the maximum number of hydrogen atoms around each carbon atom. They contain only single covalent bonds between carbon atoms, therefore they are usually alkanes. Unsaturated hydrocarbons are just the opposite and they contain double or triple bonds between carbon atoms. They are usually alkenes and alkynes.
Key terms from part II. 1. Hydrocarbon radical 2. Functional group 3. Alcohol 4. Saturated hydrocarbon 5. Unsaturated hydrocarbon
Inorganic and Organic nomenclature practice Write the missing name or molecular formula for the following. 1. Sulfur dioxide 2. Carbon dioxide 3. Phosphorus pentachloride 4. Dinitrogen tetroxide 5. Sulfur trioxide 6. H 3 C-CH 2 -OH 7. H 3 C-CH 2 -CH 2 -CH 3 8. H 3 C-CH=CH-CH 2 -CH Hexyne 10. Butyl alcohol 11. Methanol 12. Hydrosulfuric acid 13. Sulfuric acid 14. Sulfurous acid 15. Hypochlorous acid