Lecture Presentation Chapter 12 Organic Compounds Karen C

  • Slides: 93
Download presentation
Lecture Presentation Chapter 12 Organic Compounds Karen C. Timberlake General, Organic, and Biological Chemistry:

Lecture Presentation Chapter 12 Organic Compounds Karen C. Timberlake General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Topics covered in this Chapter • • 12. 1 Organic Compounds 12. 2 Alkanes

Topics covered in this Chapter • • 12. 1 Organic Compounds 12. 2 Alkanes 12. 3 Alkanes with Substituents 12. 4 Properties of Alkanes 12. 5 Alkenes and Alkynes 12. 6 Cis–Trans Isomers 12. 7 Functional Groups General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Chapter 3 Introduction to Organic Chemistry: Hydrocarbons Firefighters/emergency medical technicians are first responders to

Chapter 3 Introduction to Organic Chemistry: Hydrocarbons Firefighters/emergency medical technicians are first responders to fires, accidents, and other emergency situations. They are required to have an emergency medical technician certification in order to be able to treat seriously injured people. General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Chapter 12 Readiness Core Chemistry Skills • Drawing Lewis Structures (6. 6) • Predicting

Chapter 12 Readiness Core Chemistry Skills • Drawing Lewis Structures (6. 6) • Predicting Shape (6. 8) • Balancing a Chemical Equation (7. 1) General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

12. 1 Organic Compounds Organic chemistry is the study of carbon compounds. Organic compounds

12. 1 Organic Compounds Organic chemistry is the study of carbon compounds. Organic compounds such as vegetable oil contain carbon and hydrogen and are not soluble in water. Learning Goal Identify properties characteristic of organic or inorganic compounds. General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Organic Compounds An organic compound • Always contains carbon and hydrogen atoms. • May

Organic Compounds An organic compound • Always contains carbon and hydrogen atoms. • May also contain other nonmetals such as oxygen, sulfur, nitrogen, phosphorus, or a halogen. • is often found in common products such as gasoline, medicines, shampoos, plastics, and perfumes. We organize organic compounds by their functional groups, which are groups of atoms bonded in a specific way. Compounds that contain the same functional group have similar physical and chemical properties. General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Properties of Organic Compounds Organic compounds typically • Have covalent bonds. • have low

Properties of Organic Compounds Organic compounds typically • Have covalent bonds. • have low melting and boiling points. • are flammable and undergo combustion. • are not soluble in water. Vegetable oil is a mixture of organic compounds and is not soluble in water. General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Organic and Inorganic Compounds Many inorganic compounds have high melting and boiling points. Inorganic

Organic and Inorganic Compounds Many inorganic compounds have high melting and boiling points. Inorganic compounds that are ionic are usually soluble in water, and most do not burn in air. Propane, C 3 H 8, is an organic compound used as a fuel. Na. Cl, salt, is an inorganic compound composed of Na+ and Cl− ions. General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Properties of Organic and Inorganic Compounds General, Organic, and Biological Chemistry: Structures of Life,

Properties of Organic and Inorganic Compounds General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Study Check Identify each characteristic as most typical of compounds that are inorganic or

Study Check Identify each characteristic as most typical of compounds that are inorganic or organic. A. It has a high melting point. B. It is not soluble in water. Inorganic Organic C. It contains carbon and hydrogen atoms. D. It has the formula Mg. Cl 2. E. It burns easily in air. General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake Organic Inorganic Organic © 2016 Pearson Education, Inc.

Representations of Organic Compounds Hydrocarbons are organic compounds that contain only carbon and hydrogen.

Representations of Organic Compounds Hydrocarbons are organic compounds that contain only carbon and hydrogen. • In organic molecules, every carbon has four bonds. • In methane (CH 4), the carbon atom forms an octet by sharing its four valence electrons with four hydrogen atoms. Three-dimensional and two-dimensional representations of methane: (a) space-filling model, (b) ball-and-stick model, (c) wedge–dash model, (d) expanded structural formula, and (e) condensed structural formula. General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Carbon Compounds: Methane (CH 4) Structures are most often represented using their corresponding two-dimensional

Carbon Compounds: Methane (CH 4) Structures are most often represented using their corresponding two-dimensional formulas. • The expanded structural formula shows all of the atoms and the bonds connected to each atom. • A condensed structural formula shows the carbon atoms each grouped with the attached number of hydrogen atoms. General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake CH 4 © 2016 Pearson Education, Inc.

Carbon Compounds: Methane (CH 4) In methane (CH 4), carbon forms four covalent bonds

Carbon Compounds: Methane (CH 4) In methane (CH 4), carbon forms four covalent bonds to hydrogen. Methane is tetrahedral and has bond angles of 109°. A hydrocarbon is referred to as a saturated hydrocarbon when all the bonds in the molecule are single bonds. General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Carbon Compounds: Ethane (C 2 H 6) In ethane (C 2 H 6), each

Carbon Compounds: Ethane (C 2 H 6) In ethane (C 2 H 6), each tetrahedral carbon forms three covalent bonds to hydrogen and one to the other carbon. Three-dimensional and two-dimensional representations of ethane: (a) space-filling model, (b) ball-and-stick model, (c) wedge–dash model, (d) expanded structural formula, and (e) condensed structural formula. General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Study Check In the butane molecule (C 4 H 10), predict the shape around

Study Check In the butane molecule (C 4 H 10), predict the shape around each carbon atom. Each carbon atom has four single covalent bonds and, therefore, a tetrahedral shape. General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Hydrocarbons Functional Alkanes (C-C) Single bonds Groups Alkenes (C=C) Double bonds Alkynes (CΞC) Triple

Hydrocarbons Functional Alkanes (C-C) Single bonds Groups Alkenes (C=C) Double bonds Alkynes (CΞC) Triple bonds Benzene Rings - Aromatic General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

12. 2 Alkanes A large number of carbon compounds are possible because the covalent

12. 2 Alkanes A large number of carbon compounds are possible because the covalent bonds between carbon atoms, such as those in propane (C 3 H 8), are very strong, allowing carbon atoms to form long, stable chains Learning Goal Write the IUPAC names and draw the condensed structural formulas and skeletal formulas for alkanes and cycloalkanes. General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Alkanes • are formed by a continuous chain of carbon atoms. • are named

Alkanes • are formed by a continuous chain of carbon atoms. • are named using the IUPAC (International Union of Pure and Applied Chemistry) system. • have names that end in ane. (which means single bond) • use Greek prefixes to name carbon chains with five or more carbon atoms. General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

IUPAC Names of Alkanes with five or more carbon atoms in a chain are

IUPAC Names of Alkanes with five or more carbon atoms in a chain are named using Greek prefixes: pent (5), hex (6), hept (7), oct (8), non (9), and dec (10). General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Condensed Structural Formulas In a condensed structural formula, • each carbon atom and its

Condensed Structural Formulas In a condensed structural formula, • each carbon atom and its attached hydrogen atoms are written as a group. • a subscript indicates the number of hydrogen atoms bonded to each carbon atom. Core Chemistry Skill Naming and Drawing Alkanes General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Line-Angle Structural Formulas A simplified structure of organic molecules • is called the line-angle

Line-Angle Structural Formulas A simplified structure of organic molecules • is called the line-angle structural formula. • shows a zigzag line in which carbon atoms are represented as the ends of each line and as corners. Carbon atoms • at the end are bonded to three hydrogen atoms. • in the middle are bonded to two hydrogen atoms. General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Guide to Drawing Structural Formulas for Alkanes General, Organic, and Biological Chemistry: Structures of

Guide to Drawing Structural Formulas for Alkanes General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Drawing Expanded, Condensed, and Line. Angle Structural Formulas Draw the expanded, condensed, and line-angle

Drawing Expanded, Condensed, and Line. Angle Structural Formulas Draw the expanded, condensed, and line-angle structural formula for pentane. STEP 1 Draw the carbon chain. A molecule of pentane has five carbon atoms in a continuous chain. STEP 2 Draw the expanded structural formula by adding the hydrogen atoms, usingle bonds to each of the carbon atoms. General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Drawing Expanded, Condensed, and Line. Angle Structural Formulas Draw the expanded, condensed, and line-angle

Drawing Expanded, Condensed, and Line. Angle Structural Formulas Draw the expanded, condensed, and line-angle structural formula for pentane. STEP 3 Draw the condensed structural formula by combining the H atoms with each C atom. General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Drawing Expanded, Condensed, and Line. Angle Structural Formulas Draw the expanded, condensed, and line-angle

Drawing Expanded, Condensed, and Line. Angle Structural Formulas Draw the expanded, condensed, and line-angle structural formula for pentane. STEP 4 Draw the line-angle structural formula as a zigzag line in which the ends and corners represent C atoms. General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Conformations of Alkanes Carbon atoms in a chain, connected by single C — C

Conformations of Alkanes Carbon atoms in a chain, connected by single C — C bonds • can rotate so that groups attached to each carbon move freely about the C — C bond. • can have different arrangements known as conformations. As the — CH 3 groups rotate about the single C — C bond, they appear at different angles. General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Structural Formulas: C 4 H 10 As butane (C 4 H 10) rotates, sometimes

Structural Formulas: C 4 H 10 As butane (C 4 H 10) rotates, sometimes the — CH 3 groups line up in front of each other, and at other times they are opposite each other. Butane can be drawn using a variety of twodimensional condensed structural formulas: General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Cycloalkanes • are cyclic alkanes. • have two fewer hydrogen atoms than the open

Cycloalkanes • are cyclic alkanes. • have two fewer hydrogen atoms than the open chain form. • are named by using the prefix cyclo before the name of the alkane chain with the same number of carbon atoms. propane (C 3 H 8) cyclopropane (C 3 H 6) General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Formulas of Cycloalkanes General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C.

Formulas of Cycloalkanes General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Study Check Give the IUPAC name for each of the following compounds: A. an

Study Check Give the IUPAC name for each of the following compounds: A. an alkane with eight continuous carbon atoms is octane. B. A cyclic molecule with five carbons is cyclopentane. General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Study Check Name the following alkanes: A. CH 3−CH 2−CH 3 B. Butane Cyclopropane

Study Check Name the following alkanes: A. CH 3−CH 2−CH 3 B. Butane Cyclopropane C. CH 3−CH 2−CH 2−CH 3 D. General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake Octane Cyclohexane © 2016 Pearson Education, Inc.

12. 3 Alkanes with Substituents When an alkane has four or more carbon atoms,

12. 3 Alkanes with Substituents When an alkane has four or more carbon atoms, the atoms can be arranged so that a side group called a branch or substituent is attached to a carbon chain. Learning Goal Write the IUPAC names for alkanes with substituents and draw their condensed and line-angle structural formulas. General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Structural Isomers Structural isomers • have the same molecular formula with a different arrangement

Structural Isomers Structural isomers • have the same molecular formula with a different arrangement of atoms. • have the same number of atoms bonded in a different order. Butane (C 4 H 10) has two structural isomers: a straight chain and a branched chain. General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Study Check Draw three possible structural isomers of pentane (C 5 H 12). General,

Study Check Draw three possible structural isomers of pentane (C 5 H 12). General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Alkane Substituents are atoms or groups of atoms attached to the carbon chain and

Alkane Substituents are atoms or groups of atoms attached to the carbon chain and include alkyl and halo groups. Alkyl groups are • groups of carbon atoms attached to carbon chains. • named in the IUPAC system with an yl ending. Halo substituents are • halogen atoms attached to the carbon chain. • named in the IUPAC system as fluoro, chloro, bromo, or iodo. General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Substituents and Alkyl Groups General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen

Substituents and Alkyl Groups General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Guide to Naming Alkanes with Substituents General, Organic, and Biological Chemistry: Structures of Life,

Guide to Naming Alkanes with Substituents General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Study Check Give the IUPAC name for the following compound: STEP 1 ANALYZE THE

Study Check Give the IUPAC name for the following compound: STEP 1 ANALYZE THE name PROBLEM Given five-carbon chain, Need IUPAC one methyl group, one halo group General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Solution STEP 2 Number the carbon atoms, starting from the end nearest a substituent.

Solution STEP 2 Number the carbon atoms, starting from the end nearest a substituent. pentane STEP 3 Give the location and name of each substituent (in alphabetical order) as a prefix to the name of the main chain. 2 -chloro-3 -methylpentane General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Naming Cycloalkanes with Substituents When one substituent is attached to a carbon atom in

Naming Cycloalkanes with Substituents When one substituent is attached to a carbon atom in a cycloalkane, • the name of the substituent is placed in front of the cycloalkane name. • no number is needed for a single alkyl group or halogen atom. The IUPAC name for the following cycloalkane is ethylcyclohexane. General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Naming Haloalkanes • are alkanes with a halogen atom that replaces a hydrogen atom.

Naming Haloalkanes • are alkanes with a halogen atom that replaces a hydrogen atom. • are named by putting the substituents in alphabetical order. • have the halo group numbered according to the carbon where it is attached to the alkane. General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Guide to Drawing Line-Angle Formulas General, Organic, and Biological Chemistry: Structures of Life, 5/e

Guide to Drawing Line-Angle Formulas General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Drawing Line-Angle Formulas Draw the condensed and line-angle structural formulas for 2, 3 -dimethylbutane.

Drawing Line-Angle Formulas Draw the condensed and line-angle structural formulas for 2, 3 -dimethylbutane. ANALYZE THE PROBLEM Given 2, 3 -dimethylbutane Need condensed and line-angle structural formulas STEP 1 Draw the main chain of carbon atoms. For butane, draw a chain or a zigzag line of four carbon atoms. C—C—C—C General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Drawing Line-Angle Formulas Draw the condensed and line-angle structural formulas for 2, 3 dimethylbutane.

Drawing Line-Angle Formulas Draw the condensed and line-angle structural formulas for 2, 3 dimethylbutane. STEP 2 Number the chain and place the substituents on the carbons indicated by the numbers. The first part of the name indicates two methyl groups — CH 3: one on carbon 2 and one on carbon 3. General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Drawing Line-Angle Formulas Draw the condensed and line-angle structural formulas for 2, 3 dimethylbutane.

Drawing Line-Angle Formulas Draw the condensed and line-angle structural formulas for 2, 3 dimethylbutane. STEP 3 For the condensed structural formula, add the correct number of hydrogen atoms to give four bonds to each C atom. General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Study Check Draw the condensed and line-angle structural formulas for 3 -bromo-1 -chlorobutane. CH

Study Check Draw the condensed and line-angle structural formulas for 3 -bromo-1 -chlorobutane. CH 2−CH−CH 3 | | Cl Br 3 -bromo-1 -chlorobutane General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Study Check Name each of the following alkanes. A. . 2 -chloropentane B. 2,

Study Check Name each of the following alkanes. A. . 2 -chloropentane B. 2, 3 -dimethylpentane General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

12. 4 Properties of Alkanes The different uses of alkane compounds result from their

12. 4 Properties of Alkanes The different uses of alkane compounds result from their physical properties, including their solubility and density. The solid alkanes that make up waxy coatings on fruits and vegetables help retain moisture, inhibit mold, and enhance appearance. Learning Goal Identify the properties of alkanes and write a balanced equation for combustion. General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Uses of Alkanes with one to four carbons are gases at room temperature and

Uses of Alkanes with one to four carbons are gases at room temperature and are widely used as heating fuels. methane, propane, butane Butane has four carbons: Alkanes with five to eight carbons are highly volatile liquids at room temperature, which makes them useful as fuels. pentane, hexane, heptane, octane Octane has eight carbons: General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Uses of Alkanes with 9− 17 carbons are liquids with higher boiling points and

Uses of Alkanes with 9− 17 carbons are liquids with higher boiling points and are found in motor oils, mineral oil, kerosene, diesel, and jet fuels. Decane has 10 carbons: • Alkanes with 18 or more carbon atoms, known as paraffins, are waxy solids at room temperature. • Petroleum jelly, or Vaseline, is a semisolid mixture of hydrocarbons with more than 25 carbon atoms. General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Melting and Boiling Points Alkanes • have the lowest melting and boiling points of

Melting and Boiling Points Alkanes • have the lowest melting and boiling points of organic compounds. • contain only the nonpolar bonds of C — C and C — H. • exhibit only weak dispersion forces in the solid and liquid states. Longer-chain alkanes have more dispersion forces. General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Melting and Boiling Points Branched alkanes • have lower boiling points than the straight-chain

Melting and Boiling Points Branched alkanes • have lower boiling points than the straight-chain isomers. • tend to be more compact, reducing the points of contact between the molecules. • do not have linear shapes and cannot line up close to each other. General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Melting and Boiling Points Cycloalkanes • have higher boiling points than the straight-chain alkanes

Melting and Boiling Points Cycloalkanes • have higher boiling points than the straight-chain alkanes with the same number of carbon atoms. • have limited rotation of carbon bonds; they maintain their rigid structure and can be stacked closely together, which gives them many points of contact and attractions to each other. General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Melting and Boiling Points We can compare the boiling points of straight-chain alkanes, branched-chain

Melting and Boiling Points We can compare the boiling points of straight-chain alkanes, branched-chain alkanes, and cycloalkanes. General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Combustion of Alkanes The carbon–carbon single bonds in alkanes are difficult to break, which

Combustion of Alkanes The carbon–carbon single bonds in alkanes are difficult to break, which makes them the least reactive family of organic compounds. However, alkanes burn readily in oxygen to produce carbon dioxide, water, and energy. Δ Alkane(g) + O 2(g) General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake CO 2(g) + H 2 O(g) + energy © 2016 Pearson Education, Inc.

Combustion of Alkanes Methane is the natural gas we use to cook our food

Combustion of Alkanes Methane is the natural gas we use to cook our food and heat our homes. The equation for the combustion of methane (CH 4) is written as follows: Δ CH 4(g) + 2 O 2(g) CO 2(g) + 2 H 2 O(g) + energy Propane is the gas used in portable heaters and gas barbecues. The equation for the combustion of propane (C 3 H 8) is written as follows: CH 4(g) + 5 O 2(g) Δ General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake 3 CO 2(g) + 4 H 2 O(g) + energy © 2016 Pearson Education, Inc.

Solubility and Density of Alkanes are • nonpolar. • insoluble in water. • less

Solubility and Density of Alkanes are • nonpolar. • insoluble in water. • less dense than water. • flammable in air. • found in crude oil. If there is an oil spill in the ocean, the alkanes in the crude oil do not mix with the water but float on top, forming a thin layer on the surface. General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Oil Spills In April 2010, an explosion on an oil-drilling rig in the Gulf

Oil Spills In April 2010, an explosion on an oil-drilling rig in the Gulf of Mexico caused the largest oil spill in U. S. history, spilling at its maximum about 10 million liters per day. Cleaning up an oil spill includes the following processes: • mechanical—a boom may be placed around the oil so that boats called skimmers can scoop it up and place it in tanks. • chemical—a substance that attracts oil is used to pick up the oil, which is then scraped off into recovery tanks. • microbiological—certain bacteria that ingest oil are used to break oil down into less harmful products. General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Study Check Butane (C 4 H 10) is a fuel often used in lighters.

Study Check Butane (C 4 H 10) is a fuel often used in lighters. Write a balanced equation for the complete combustion of butane. 2 C 4 H 10(g) + 13 O 2(g) 8 CO 2(g) + 10 H 2 O(g) General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

12. 5 Alkenes and Alkynes Ethyne, commonly called acetylene, is used in welding, in

12. 5 Alkenes and Alkynes Ethyne, commonly called acetylene, is used in welding, in which it reacts with oxygen to produce flames with temperatures above 3300 °C. Learning Goal Identify structural formulas as alkenes, cycloalkenes, and alkynes, and write their IUPAC names. General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Alkenes and Alkynes Alkenes and alkynes are families of hydrocarbons that • contain double

Alkenes and Alkynes Alkenes and alkynes are families of hydrocarbons that • contain double and triple bonds, respectively. • are called unsaturated hydrocarbons because they do not contain the maximum number of hydrogen atoms. • react with hydrogen gas to increase the number of hydrogen atoms and become alkanes. Remember, carbon atoms always form four covalent bonds. General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Identifying Alkenes contain one or more carbon–carbon double bonds. In ethene (C 2 H

Identifying Alkenes contain one or more carbon–carbon double bonds. In ethene (C 2 H 4), two carbon atoms are connected by a double bond. Each carbon atom in the double bond is attached to two hydrogen atoms and has a trigonal planar arrangement with bond angles of 120°. General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Ethene (C 2 H 4), more commonly called ethylene, • is an important plant

Ethene (C 2 H 4), more commonly called ethylene, • is an important plant hormone involved in promoting the ripening of fruits such as bananas. • accelerates the breakdown of cellulose in plants, which causes flowers to wilt and leaves to fall from trees. General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Identifying Alkynes contain one or more carbon–carbon triple bonds. In ethyne (C 2 H

Identifying Alkynes contain one or more carbon–carbon triple bonds. In ethyne (C 2 H 2), • two carbon atoms are connected by a triple bond. • each carbon is also bonded to one H atom. Each carbon atom in the triple bond has a linear arrangement with bond angles of 180°. General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Study Check Identify each of the following compounds as an alkene or alkyne: A.

Study Check Identify each of the following compounds as an alkene or alkyne: A. 3 -Octene – an alkene B. 3 - propyl-1 -heptyne an alkyne General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Naming Alkanes, Alkenes, and Alkynes The IUPAC names for alkenes and alkynes • are

Naming Alkanes, Alkenes, and Alkynes The IUPAC names for alkenes and alkynes • are similar to those of alkanes. • use the alkane name with the same number of carbon atoms, replacing the ane ending with ene. Cyclic alkenes are named as cycloalkenes. General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Guide to Naming Alkenes and Alkynes General, Organic, and Biological Chemistry: Structures of Life,

Guide to Naming Alkenes and Alkynes General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Study Check Write IUPAC names for each of the following: A. B. General, Organic,

Study Check Write IUPAC names for each of the following: A. B. General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Solution STEP 1 Name the longest carbon chain that contains the double or triple

Solution STEP 1 Name the longest carbon chain that contains the double or triple bond. ANALYZE Given Need A. THE PROBLEM five-carbon chain, double bond, methyl group IUPAC name five carbon atoms—pentene B. ANALYZE THE PROBLEM Given six-carbon chain, triple bond Need IUPAC name six carbon atoms—hexyne General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Solution STEP 2 Number the carbon chain, starting from the end nearer the double

Solution STEP 2 Number the carbon chain, starting from the end nearer the double or triple bond. A. 2 -pentene B. 2 -hexyne General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Solution STEP 3 Give the location and name of each substituent (alphabetical order) as

Solution STEP 3 Give the location and name of each substituent (alphabetical order) as a prefix to the alkeneor alkyne name. A. 4 -methyl-2 -pentene B. 2 -hexyne; there are no substituents in this compound. General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Naming Cycloalkenes have a double bond within a ring structure and • are named

Naming Cycloalkenes have a double bond within a ring structure and • are named by assigning the double bond to be between carbon 1 and carbon 2 when a substituent is on the ring. • do not need to include the numbers for the double bond. 3 -methylcyclopentene (It is understood that the double bond is between carbon 1 and carbon 2. ) The carbon atoms in the ring are numbered to give the double bond numbers 1 and 2 and the lowest possible number to any substituents present. General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Study Check Name the following alkenes and alkynes: cyclohexene General, Organic, and Biological Chemistry:

Study Check Name the following alkenes and alkynes: cyclohexene General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake 3, 3 -dimethylcyclopentene © 2016 Pearson Education, Inc.

Chemistry Link to the Environment: Fragrant Alkenes The odors you associate with lemons, oranges,

Chemistry Link to the Environment: Fragrant Alkenes The odors you associate with lemons, oranges, roses, and lavender come from the volatile compounds that are synthesized by the plants that produce these flowers and fruits. Often these compounds contain double or triple bonds or ring structures; they are unsaturated. General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

12. 6 Cis–Trans Isomers Carbon–carbon double bonds do not rotate like carbon–carbon single bonds

12. 6 Cis–Trans Isomers Carbon–carbon double bonds do not rotate like carbon–carbon single bonds do. The atoms or groups of atoms attached to the carbon atoms on the double bond may form two different structures, which are called cis–trans isomers. Learning Goal Draw the condensed and line-angle structural formulas and give the names for the cis–trans isomers of alkenes. General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Cis–Trans Isomers In an alkene, the double bond • is rigid and does not

Cis–Trans Isomers In an alkene, the double bond • is rigid and does not rotate. • holds attached groups in fixed positions. • makes cis–trans isomers (geometric isomers) possible when two different groups are attached to the carbon atoms on each side of the double bond. • requires a prefix of cis or trans to reflect the arrangement of groups across the double bond. General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Cis–Trans Isomers Cis–trans isomers • have different physical and chemical properties. • cannot occur

Cis–Trans Isomers Cis–trans isomers • have different physical and chemical properties. • cannot occur when two groups are the same on one of the carbons. General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Cis–Trans Isomers of Butene • In a cis isomer, the alkyl groups are attached

Cis–Trans Isomers of Butene • In a cis isomer, the alkyl groups are attached on the same side of the double bond and H atoms are on the other side. • In the trans isomer, the groups and H atoms are attached on opposite sides of the double bond. General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Chemistry Link to the Environment: Pheromones Many insects emit minute quantities of chemicals called

Chemistry Link to the Environment: Pheromones Many insects emit minute quantities of chemicals called pheromones to send others of the same species messages. Pheromones may • warn an insect of danger. • mark a trail. • attract the opposite sex. General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Chemistry Link to the Environment: Pheromones The effectiveness of many of these pheromones depends

Chemistry Link to the Environment: Pheromones The effectiveness of many of these pheromones depends on the cis or trans configuration of the double bonds in the molecules. One pheromone is bombykol, • the sex pheromone produced by the female silkworm moth. • which contains one cis double bond and one trans double bond. General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Naming Cis–Trans Isomers The prefix of cis or trans is placed in front of

Naming Cis–Trans Isomers The prefix of cis or trans is placed in front of the alkene name when the compound is a cis or trans isomer. cis trans cis-1, 2 -dibromoethene General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake trans-1, 2 -dibromoethene © 2016 Pearson Education, Inc.

Study Check Name each, using cis or trans prefixes when needed. A. B. C.

Study Check Name each, using cis or trans prefixes when needed. A. B. C. General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

Solution Name each, using cis or trans prefixes when needed. A. cis-2, 3 -dichlorobutene

Solution Name each, using cis or trans prefixes when needed. A. cis-2, 3 -dichlorobutene B. trans-2, 3 -dibromobutene C. trans-2 -butene General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc.

12. 7 Functional Groups Functional groups • are a characteristic feature of organic molecules

12. 7 Functional Groups Functional groups • are a characteristic feature of organic molecules that behave in a predictable way. • are composed of an atom or a group of atoms. • are groups that replace a H in the corresponding alkane. • provide a way to classify families of organic compounds. General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc. 84

Some Functional Groups General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C.

Some Functional Groups General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc. 85

Alkenes and Alkynes • Alkenes contain a double bond between adjacent carbon atoms. •

Alkenes and Alkynes • Alkenes contain a double bond between adjacent carbon atoms. • Alkynes contain a triple bond. • Aromatic compounds contain a benzene ring. © 2013 Pearson Education, Inc. Chapter 11, Section 5 86

Alcohols, Thiols, and Ethers • An alcohol contains the hydroxyl (–OH) functional group. •

Alcohols, Thiols, and Ethers • An alcohol contains the hydroxyl (–OH) functional group. • Thiols contain a thiol (– SH) functional group. • In an ether, an oxygen atom is bonded to two carbon atoms (–C–O–C–). General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake Thiol © 2016 Pearson Education, Inc. 87

Aldehydes and Ketones • An aldehyde contains a carbonyl group (C=O), which is a

Aldehydes and Ketones • An aldehyde contains a carbonyl group (C=O), which is a carbon atom with a double bond to an oxygen atom, attached to at least one hydrogen atom. • In a ketone, the carbon of the carbonyl group is attached to two other carbon atoms. General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc. 88

Carboxylic Acids and Esters • Carboxylic acids contain the carboxyl group, which is a

Carboxylic Acids and Esters • Carboxylic acids contain the carboxyl group, which is a carbonyl group attached to a hydroxyl group. • An ester contains the carboxyl group between carbon atoms. General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc. 89

Amines and Amides • In an amine, the functional group is a nitrogen atom.

Amines and Amides • In an amine, the functional group is a nitrogen atom. • In an amide, the hydroxyl group of a carboxylic acid is replaced by a nitrogen group. General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc. 90

Learning Check Classify each of the following as alcohol, ether, aldehyde, ketone, carboxylic acid,

Learning Check Classify each of the following as alcohol, ether, aldehyde, ketone, carboxylic acid, ester, or amine. A. B. C. D. General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc. 91

Solution Classify each of the following as alcohol, ether, aldehyde, ketone, carboxylic acid, ester,

Solution Classify each of the following as alcohol, ether, aldehyde, ketone, carboxylic acid, ester, or amine. A. alcohol ether B. amine C. carboxylic acid D. ester General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake © 2016 Pearson Education, Inc. 92

End of Chapter 12 Any Questions? General, Organic, and Biological Chemistry: Structures of Life,

End of Chapter 12 Any Questions? General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C. Timberlake 93 © 2016 Pearson Education, Inc.