Organic Chemistry Chapter 25 - Ms. Ose's Chemistry Website
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Transcript Organic Chemistry Chapter 25 - Ms. Ose's Chemistry Website
Objectives:
Today I will be able to:
Identify and name the functional groups in organic
compounds
Explain the definition of an isomer
Differentiate between cis and trans isomers
Informal assessment – monitoring student
interactions and questions as they complete the
practice
Formal assessment – analyzing student responses to
the practice
Common Core Connection
Make sense of problems and persevere in solving them
Reason abstactly
Lesson Sequence
Evaluate: Warm-up
Explain: Isomers, Cis vs. Trans
Explore/Explain: Functional Groups
Elaborate: Worksheet
Evaluate: Exit Ticket
Warm Up
Draw the structure and determine what is
wrong with the name
1 – ethyl -3-methyl-2-propylpentane
2-methyl-3,4-ethylnonane
2,2- dimethyl-2-pentene
Objectives
Today I will be able to:
Identify and name the functional groups in organic
compounds
Explain the definition of an isomer
Differentiate between cis and trans isomers
Homework
Cation/Anion Quiz sometime the week of September
8-11
Solubility Rule Quiz sometime the week of September
15-19
Agenda
Warm-up
Isomers, Cis vs. Trans
Functional Groups
Practice Worksheet
Exit Ticket
Complete the functional groups outline using your
textbook. We will review as a class.
Complete the practice problems at your desk. We will
review the answers as a class.
The Shapes of Organic Molecules
In the VSEPR model, the bonds to a carbon are
comprised of four electron pairs:
Single bonds: tetrahedral
One double bond: trigonal-planar
Two double bonds: linear
This helps to determine molecular shapes and how
they will react with other molecules and how quickly
The Stabilities of Organic
Substances
Triple bonds are stronger than double bonds which are
stronger than single bonds; this results from
decreasing bond length
Most reactions between oxygen and organic
compounds are exothermic and stable at room
temperature
Special stability is associated with the presence of
aromatic rings due to the overlap of the pi orbitals of
the carbon atoms that cause the electrons to delocalize
(resonance structures)
Solubility and Acid/Base Properties
of Organic Substances
Carbon Carbon and Carbon Hydrogen bonds are the
most prevalent in these substances
Overall low polarity and soluble in nonpolar solvents
Molecules are soluble in water have polar groups on the
surface of the molecule
Acidic substances: carboxylic acids –COOH
Basic substances: amines –NH2, -NHR, -NR2
Amino Acids: contain both the carboxylic acid and
amino groups; amphoteric (acting as either an acid or
base)
Introduction to Hydrocarbons
Alkanes (Ethane) CH3 CH3
http://www.knowledgerush.com/wiki_image/a/ae/Ethane.png
Alkanes
An organic compound containing only single bonds
Geometry of each carbon atom is tetrahedral with sp3
hybridization
These are considered saturated hydrocarbon
http://wpcontent.answers.com/wikipedia/commons/thumb/b/bb/Ch4_hybridization.svg/178px-Ch4_hybridization.svg.png
Alkanes
Straight chain hydrocarbons: carbons atoms are joined
in a single continuous chain
Branched chain hydrocarbons: hydrocarbon chains
with four or more atoms can form branches rather
than straight chains
Structural isomers: compounds with the same
molecular formula but different bonding
arrangements; also known as resonance structures
Nomenclature of Alkanes
1.
Find the longest carbon chain and use the number of
carbon atoms
http://image.tutorvista.com/content/organic-chemistry/alkanes-nomenclature.gif
Nomenclature of Alkanes
2. Number the carbon atoms with the lowest number at
the closest substituent
3. Name the substituent groups and if there is more
than one group list them in alphabetical order with
the carbon number attached
Alkyl group: removing an H atom from an alkane to
form a substituent group
Cycloalkanes
Cycloalkanes are rings or cycles of alkanes
These are shown as simple polygons when they are
drawn
Rings with less than five atoms are considered
unstable
Most cycloalkanes behave like unsaturated
hydrocarbons
http://www.chemguide.co.uk/organicprops/alkanes/cyclos.gif
Alkane Reactions
Alkanes are relatively unreactive because of their
stable state
Combustion: basic reaction for use of fuels
http://www.elmhurst.edu/~chm/onlcourse/chm110/labs/world3images/lab2b.GIF
Alkenes
An unsaturated hydrocarbon with a double carbon
carbon bond
http://upload.wikimedia.org/wikipedia/commons/8/8d/Ethylene-2D.png
Alkene
There are several isomers that exists for an alkene
when there are four or more carbon atoms
Geometric isomers: compounds that have the same
molecular formula and the same groups bonded but
different spatial arrangements; results from the carbon
carbon double bond’s resistance to twisting
Alkynes
An unsaturated hydrocarbon containing a triple
carbon carbon bond
These compounds are highly reactive
http://wikipremed.com/image_science_archive_th/030101_th/197600_800px-Acetylene-
Aromatic Hydrocarbons
Are planar rings with a sigma and pi bond
Chart of common aromatic ring systems are on page
977
http://www.chem.lsu.edu/lucid/courseinfo/chem1002/Image20.gif
Functional Groups:
Alcohols and Ethers
A functional group is a site
of reactivity in an organic
molecule that controls how a
molecule behaves and
functions
See page 980 for reference to
chart
Alcohols
Alcohols are hydrocarbon derivatives in which one or
more hydrocarbons of a parent hydrocarbon have been
replaced by an –OH (hydroxyl group)
http://z.about.com/d/chemistry/1/0/f/m/aceticacid.jpg
Ethers
Ethers are compounds in which two hydrocarbon
groups are bonded to one oxygen; can be formed from
two molecules of alcohol by splitting out a molecule of
water
http://upload.wikimedia.org/wikipedia/commons/0/0e/Dimethyl-ether-2D-
Compounds with a Carbonyl Group
A carbonyl group is a functional group that contains a
carbon oxygen double bond
C=O
Aldehydes: have at least one hydrogen atom attached
to the molecule
Ketones: Occurs at the interior of a carbon chain,
therefore enclosed by carbon atoms
Aldehydes and Ketones
Aldehyde
Ketone
http://www.chemistry-drills.com/icons/1.JPG
http://upload.wikimedia.org/wikipedia/commons/4/48/Ketone-general.png
Carboxylic Acids
These acids contain the carboxyl functional group
(-
COOH) and can be produced by the oxidation of
alcohols
http://www.biology.lsu.edu/introbio/Link2/fatty%20acids.gif
Esters
Carboxylic acid that undergo condensation reaction
with alcohols
Hydrolysis of an ester in the presence of a base is called
saponification
http://www.wiredchemist.com/images/structure5.
Amines and Amides
Amines are organic bases and amides are the products
of a condensation reaction between an amine and a
carboxylic acid
http://z.about.com/d/chemistry/1/0/r/s/tertiaryaminegroup.j