chapter 20 organic chemistry objective: students will understand how to name the alkanes
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Chapter 20Chapter 20
Organic Chemistry
Objective: Students will understand how to name the alkanes.
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BOOKS!BOOKS!
THOSE WHO CHECKED OUT A BOOK!TURN IN YOUR BOOK NEXT TIME
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What is ORGANIC Chemistry?What is ORGANIC Chemistry?
The study of carbon-containing compounds (typically chains of carbon atoms) and their properties.
Carbon atoms can link to other carbon atoms indefinitely.
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HYDROCARBONSHYDROCARBONS
Compounds containing carbon and hydrogen only. There are several classes.
The first is ALKANES.
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ALKANESALKANESAlkanes are the simplest of the hydrocarbons.
They only contain carbon-hydrogen bonds and carbon-carbon single bonds. The first ten are:
Their formulas are alwaysCxH2x+2 C6H14 is an example
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TEN ALKANESTEN ALKANES
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The names of the Alkanes always end in -ane
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Figure 20.2: The Lewis structure of ethane.Figure 20.2: The Lewis structure of ethane.
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Name the CompoundName the Compound
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What is a branched-chained alkane?What is a branched-chained alkane?
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Naming Branched Naming Branched Chained AlkanesChained Alkanes
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Naming Branched Naming Branched Chained AlkanesChained Alkanes
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Naming Branched Naming Branched Chained AlkanesChained Alkanes
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Naming Branched Naming Branched Chained AlkanesChained Alkanes
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Name the CompoundName the Compound
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Name The CompoundName The Compound
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Calculating the molar-mass Calculating the molar-mass Branched Chained AlkanesBranched Chained Alkanes
Calculating the molar mass of alkanes is easy.1. Determine the total number of carbons and
times that number by 12.2. Then determine the number of hydrogens.
( 2x the carbons + 2 more)3. Add the two together.
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Calculating the molar-mass Calculating the molar-mass Branched Chained AlkanesBranched Chained Alkanes
Example:Find the molar-mass of 2,3-dimethylpentane.
There are 5 carbons in pentane and 1 carbon in each methyl so a total of 7.
That means there are a total of 16 hydrogen atoms.
12 x 7 + 16 = 84 + 16 = 100
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Isotopes of ButaneIsotopes of Butane
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Stop here for the 1Stop here for the 1stst Assignment Assignment
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Start here for the 2Start here for the 2ndnd Assignment Assignment
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For this day we will draw and name the isomers of Heptane.Then we will learn how to identify and name ALKENES and ALKYNESThere is a clicker quiz named “ALKENES AND ALKYNES”
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ISOMERSISOMERS
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ISOMERSISOMERS
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In class assignmentDraw and name the nine isomers of Heptane C7H16
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What is a BLEVE?What is a BLEVE?
An acronym for “boiling liquid escaping vapor explosion
VIDEO #1Video #2 The jet sound is a bleve!Video #3 Notice how the fire keeps its
shape? That’s because the fuel must mix with oxygen in just the right ratio
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A closer look at this fireA closer look at this fire
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PropanePropane
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Properties of ALKANESProperties of ALKANES
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AlkenesAlkenes
Alkenes are hydrocarbons with double bonds. They are unsaturated and often referred to as “olefins”
The name of alkenes end in –ene.Ethene, Propene Butene Pentene
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Cis and TransCis and Trans
Double bonds on the carbons prevents the carbon atoms from rotating around each other.
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Naming AlkenesNaming Alkenes
When naming alkenes give the lowest number to the double bond.
Then name the side chains
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Name the compoundName the compound
Trans-3-heptene4-methyl-cis-2 pentene
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ButadieneButadiene
Butadiene is butane with two double bondsC=C-C=C 2,3-butadiene
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Cyclo-hydrocarbons Cyclo-hydrocarbons
Hydrocarbons that are in a ring are called cyclo-hydrocarbons
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AlkynesAlkynes
Alkynes are hydrocarbons that have a triple bond. They are very reactive.
Video controlled explosion of ethyne.
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Naming Aromatic Compounds Naming Aromatic Compounds BENZENEBENZENE
Objective: Students will understand the historical significance of Benzene, its structure and how to name compounds containing benzene.
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Figure 20.8: Two Lewis structures for the benzene ring.Figure 20.8: Two Lewis structures for the benzene ring.
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1.3.5-Cyclohexatriene.1.3.5-Cyclohexatriene.
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Early usesEarly uses
In the 19th and early-20th centuries, benzene was used as an after-shave lotion because of its pleasant smell. Prior to the 1920s, benzene was used as an industrial solvent. To decaffeinate coffee
Later benzene was used to improve the anti-knock in gasoline.
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Benzene is an AROMATIC CompoundBenzene is an AROMATIC Compound
The term 'aromatic' was assigned before the physical mechanism determining aromaticity was discovered, and was derived from the fact that many of the compounds have a sweet scent.
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Benzene Benzene
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Tylenol and AdvilTylenol and Advil
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TolueneTolueneWhen a methyl group is attached to a benzene
ring, the whole structure is referred to as toluene.
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This is the #1 Carbon
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Naming Compounds Containing TolueneNaming Compounds Containing Toluene
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toluene
2 chloro-toluene
2,3 dichloro-toluene
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2,4,6-trinitrotoluene2,4,6-trinitrotoluene
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Phenyl GroupsPhenyl Groups
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Petroleum Petroleum This is a mixture of many compounds taken
out of the earth and separated into purer compounds by means of a distillation tower.
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Figure 20.7: Benzene CFigure 20.7: Benzene C66HH66..
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Figure 20.8: Shorthand notation for benzene rings.Figure 20.8: Shorthand notation for benzene rings.
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Figure 20.10: Figure 20.10: Names of Names of
some some common common
monosubstitutmonosubstituted benzenes.ed benzenes.
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Figure 20.5: Energy sources used in the United States.Figure 20.5: Energy sources used in the United States.
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Figure 20.6: Ball-and-stick model of ethylene.Figure 20.6: Ball-and-stick model of ethylene.
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Figure 20.13: Figure 20.13: Some carboxylic Some carboxylic
acids.acids.
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Table 20.5Table 20.5
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What is an Alcohol? What is an Alcohol?
Alcohols: Contain the hydroxyl functional group, –OH which replaces an –H in the alkane.
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How to name AlcoholsHow to name Alcohols
Alcohols are named by replacing the “-e” ending of the alkane with a “-ol” ending.
• methane, CH4, gives methanol, CH3OH
• ethane, C2H6, gives ethanol, C2H5OH
• Propane, , gives 2-propanol,
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Organic AcidsOrganic Acids
Organic Acids Contain the carboxyl Functional Group, –COOH
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What is a Keytone?What is a Keytone?
Ketones: Have the carbonyl functional group bonded between two hydrocarbon units.
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Naming KeytonesNaming Keytones
Ketones are named by replacing the -e ending of the alkane with the -one ending and prefixing the name with the number of the carbonyl carbon
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Aldehydes Aldehydes
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Figure 20.9: The bonding in the benzene ring is a combination of different Lewis structures.Figure 20.9: The bonding in the benzene ring is a combination of different Lewis structures.