Transcript Organic Chemistry : Ch. 19

Organic Chemistry : Ch. 19
 Organic chemistry is the
branch of chemistry which
deals with “carbon based”
compounds.
 Carbon is an element
which has the unique
ability to bond long chains,
rings, and react with other
elements to form a variety
of compounds.
Carbon Compounds
 Carbon compounds are
found in many forms :
gases, aqueous, and solids.
 Carbon is recycled in
nature by the carbon cycle.
 Carbon chains can be
modified by reactions to
form different type of
carbon based (organic)
compounds.
Story of Carbon
 Carbon is a major component
of living things.
 Lipids (fats and oils), sugars,
starches, proteins, DNA, etc.
are composed of carbon,
hydrogen, oxygen, nitrogen,
and other atoms.
 Lipids, sugars, and starches
are composed of carbon,
hydrogen, and oxygen.
 Proteins are composed of
carbon, hydrogen, oxygen,
nitrogen, and sometimes
sulfur.
Story of Carbon
 When organisms die and
decompose in a low oxygen
environment, these carbon
compounds(with the aide of
anaerobic bacteria) will
break off the oxygen,
nitrogen, and other atoms
bonded to the compounds.
Animal Fat (one
molecule)
Story of Carbon
 When the oxygen,
nitrogen, sulfur, and other
atoms are removed by
bacteria, what is left is a
hydrocarbon ( Carbon and
hydrogen only)
 These hydrocarbons are of
mixed sizes, and are known
as “crude oil” when
recovered from the earth.
Hydrocarbons : C & H atoms
Story of Carbon
 Carbon atoms have four
electrons in their outer
energy level, and will want
to covalently bond (share
electrons) with itself and
other atoms to form more
stable chain and ring
compounds.
 The crude oil contains a
mixture of hydrocarbons
including : butane(lighter
fluid), gasoline, diesel,
candle wax, etc.
Story of Carbon
 The hydrocarbons found in
crude oil can be separated
based upon their boiling
points and refined or
distilled.
 By adding substances to
them a host of other
organic compounds can be
produced : (alcohols,
esters, ethers, plastic,
styrofoam, etc.)
Hydrocarbons
 Hydrocarbons are a class of organic compounds
which contain only carbon and hydrogen.
 Hydrocarbons are characterized as carbon chains,
branched chains, and rings.
Hydrocarbons
 Carbon has 4 valence electrons and will form 4
covalent bonds with hydrogen. A line between
carbon and another atom represents the sharing of 2
electrons. Therefore every carbon in an organic
compound needs 4 lines around it.
 Hydrocarbons with all single carbon bonds are
described as the Alkanes.
 http://www.nyu.edu/pages/mathmol/library/hydrocarbons/
Journal Activity #1
 In your journal prepare a data table which shows
the following : Fill in the information for methane
through decane. Use the website given to find the
uses for.
Alkane Name
Structural Formula
Molecular Formula
Uses For
Hydrocarbons : Alkenes
 Carbon atoms have the ability to bond with other
atoms with single, double, or even triple bonds.
 When carbon bonds to another carbon with a
double bond, and only carbon and hydrogen atoms
are in a compound it’s termed an alkene.
 Ethylene(ethene) is the simplest alkene.
http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/E/
Ethylene.html
Journal Activity #2
• In your journal fill in the data table below for the
alkenes ( ethene – octene)
Name
Structural Formula
Molecular Formula Uses
Alkynes
 Alkynes are hydrocarbons which contain a triple
bond between carbons.
 Alkynes end in “yne”.
 Ethyne, Propyne, Butyne, etc.
Journal Activity #3
 Diagram the following hydrocarbons:
a) Propene
b) Butyne
c) 2 hexene
d) 2 - octyne
Journal Activity #4

http://www.ausetute.com.au/ethene.html
•
Using the website above to answer the questions below in
regards to ethene or ethylene.
Explain how ethene can be made into ethanol.
Explain how ethene can be made into ethylene glycol
(antifreeze).
What is ethene extracted from?
Describe one other chemical which can be produced from
ethyene.
a)
b)
c)
d)
Branched Hydrocarbons
 Hydrocarbons come in a variety of forms.
 Not all hydrocarbons are linear, some are branched and some are
cyclic.
 Branched hydrocarbons have a carbon “backbone” with “groups”
attached to this backbone.
 To name these compounds you need to follow the basic rules
below: (IUPAC)
 Find the longest carbon chain (backbone) and write its
corresponding name.
 Identify the groups attached to this chain.
 Assign the carbons in the chain numbers, which make the “group”
have the lowest number.
 Identify any double or triple bonds with the corresponding carbon
number.
Journal Activity #5
 Diagram the following branched hydrocarbons:
a) 2 methyl, hexane
b) 2,2, dimethyl pentane
c) 2,3 dimethyl octane
d) 2,4 dimethyl 3-decene
Branched Hydrocarbons
 Branched hydrocarbons are
found in crude oil and can
also by synthesized by
chemical reactions.
 Hydrocarbons with only
single bonds are termed
“saturated” hydrocarbons.
 Hydrocarbons with a
double or triple bond are
called “unsaturated”
hydrocarbons.
Saturated hydrocarbon : Pentane
Isomers

Diagram the following hydrocarbons :
a) Butane
•
•
•
b) 2-methyl propane
The molecular formula for both of these is C4H10
Even though the formula is the same the properties of these
compounds is very different.
This is an example of isomers. Isomers are compounds with the
same formula but different chemical and physical properties.
(Boiling point, etc…)
Journal Activity #6
 Diagram a pentane molecule, and two isomers of
this molecule. Name each isomer.
Aromatic Hydrocarbons
 Hydrocarbons can also
form ring structures.
 The simplest would be
cyclopropane, cyclobutane,
and cyclopentane.
 When six carbons form a
ring we enter a new class
of hydrocarbons called
“aromatic”
hydrocarbons.
 Benzene is the first
member of aromatic
hydrocarbons.
Journal Activity #7
 Diagram the following cyclic hydrocarbons and
give the molecular formula of each.
a) Cyclopentane
b) cyclobutene
c)
Benzene
d) cyclohexane
Benzene
 Benzene is a member of the aromatic (ring)
hydrocarbons.
 These hydrocarbons have a variety of uses as
pesticides, flavorings, and a host of other uses.
Journal Activity #8
 http://www.uyseg.org/greener_industry/pages/benze
ne/2BenzeneUses.htm
* Use the website above to describe how benzene is
used to produce : styrene, nylon rope, dynamite
(TNT), and 2,4 D( weed killer).
Hydrocarbon Summary
 At this point we’ve concluded our study of hydrocarbons.
Below is a summary of the hydrocarbon compounds we’ve
studied:

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
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Alkanes
Alkenes
Alkynes
Branched alkanes, alkenes, alkynes
Cyclic hydrocarbons
Aromatic hydrocarbons
Hydrocarbon Tutorial Websites
 http://chemed.chem.purdue.edu/genchem/topicrevie
w/bp/1organic/organic.html
• Provides a good overview of hydrocarbons with
naming practice.
• http://www.ausetute.com.au/namsanes.html
* Great web-site for all concepts of chemistry. Choose
a tutorial from the drop down on alkanes, alkenes,
etc.
Organic Compounds
 Hydrocarbons are used to synthesize a large amount
of different organic compounds.
 In addition some of these organic compounds are
naturally produced in living things.
 By adding substances and breaking bonds the
hydrocarbon can become a new “class” of organic
compound.
Organic Compounds
 The organic compounds we will study include:
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Alcohols
* sugars
Aldehydes
* starches
Amine’s
* lipids
Carboxylic Acids (Organic Acids)
Esters
* proteins
Ethers
Ketones
Alcohols
 Alcohols can be produced 3 different ways.
Alcohols are compounds with an OH functional
group (Hydroxyl) on a carbon skeleton.
C- C–
OH
Hydroxyl Group
(Alcohol)
Alcohol Properties
 Alcohols with up to 4 carbon atoms are soluble in
water as a result of the OH group on the carbon
chain.
 As more carbon atoms are added to the chain the
solubility decreases.
 Alcohols have higher boiling points than do the
hydrocarbons from which they are formed from.
Types of Alcohols
 There are three types of alcohols: Primary,
Secondary, and tertiary. These types of alcohols are
determined by “where” the OH is on the carbon
chain.
 Primary : OH is at the end of a carbon chain.
 Secondary: OH is in the middle, with 2 C atoms
attached to the C with the OH.
 Tertiary : OH is in the middle with 3 C atoms
attached to the C with the OH.
Alcohol Types
 Diagram a primary alcohol below : ( ethanol)
• Diagram a secondary alcohol below: (2 – butanol)
* Diagram a tertiary alcohol below: 2-methyl-2-propanol
Naming Alcohols
 Alcohols are named by finding their hydrocarbon skeleton
and ending this with “ol”.
 The OH group is identified to which carbon in the chain it is
attached to.
Name the following alcohol and identify it as primary,
secondary, or tertiary.
Diols/Triols
 Alcohols can have more than one OH group on a
hydrocarbon chain.
 Alcohols with two OH’s are called diols, and the
prefix di is added before the “ol” in naming.
 Alcohols with three OH’s are called triols, and the
prefix “tri” is added before the “ol” in naming.
Write the structural formula for 1,2-ethanediol. This is
also known as ethylene glycol or antifreeze.
Naming and Classifying
Alcohols
1) Draw the structural formula for the following
alcohols and classify them:
a) 3-hexanol
b) methanol
c) 1,2,3-propanetriol (glycerol)
Alcohol Formation
 Alcohols can be produced three ways :
1) From using bacteria or yeast in the process of
fermentation. (ethanol and carbon dioxide are the
waste products of yeast as they eat sugar) 12%
2) Addition of water to an alkene. (with an acid
catalyst)
3) Hydrolysis of a halocarbons.
Alcohol Formation
• Diagram the formation of ethanol from ethene +
water ( with an acid catalyst H2SO4)
* Diagram the formation of ethanol from the
hydrolysis (splitting by water) of chloroethane.
Helpful Websites for Alcohols
 http://dl.clackamas.cc.or.us/ch106-03/nomencla.htm
http://jchemed.chem.wisc.edu/JCESoft/CCA/CCA5/M
AIN/HOME.HTM
Halocarbons
 Halocarbons are organic compounds in which
halogens have replaced hydrogen.
 Halocarbons are named as to where the halogens are
attached, and how many halogens there are.
 The halogen prefix is used : fluoro, chloro, bromo,
etc.
Halocarbon Uses
 Halocarbons are used
extensively as pesticides,
insecticides, dry cleaning,
and other areas.
 Many of the most toxic
chemicals have been
halocarbons.
 PCB’s : poly chlorinated
biphenols, are toxic
synthesized halocarbons.
DDT: 1,1,1-trichloro-2,2-bis(pchlorophenyl) ethane
DDT : a halocarbon which
was banned in 1972
PCB’s
 PCB’s are halocarbons
which contain two phenols
with chlorine on them.
 PCB’s have been shown to
be accumulative in fatty
tissue, and bioaccumulate.
 The biphenols typically can
persist in soil for 15-25
years.
Naming Halocarbons
 Draw the structure for the following :
a) Trichloromethane (chloroform)
b) Tetraiodomethane:
c) 2-fluoro pentane
Ethers
 Ethers are organic compounds which have an oxygen atom
bonded to two different carbons.
 Ethers are named by naming the compound on each side and
ending in “ether”. Or by writing the short version of each
with “oxy” in the middle.
 Ethers were used anesthetics, but safer gases have been
found.
 Small ethers are soluble in water, but larger ethers are
insoluble.
 Applications of ethers are solvents, gasoline additive, etc.
Naming Ethers
•
Draw the structural diagram for the following :
a) Dimethyl ether
b) methoxypentane
c) Diethyl ether
d) Diphenyl ether
Aldehydes
 Aldehydes are organic compounds which have a
carbonyl group(C=O) at the end of a carbon chain.
 Aldehydes are named by ending the molecule with
an “al”.
Diagram ethanal, and propanal below:
Uses of Aldehydes
 Aldehydes are used as preservatives, flavorings,
perfumes, etc.
 Vanilla flavoring and cinnamon are natural aldehyde
flavors.
 Ethanol is converted to acetaldehyde (propanal) in
the human body.
Ketones
 Ketones are a class of organic compounds with a
carbonyl group (C=O) in the middle of a carbon
chain. (Ketones are never alone)
 Propanone is the simplest ketone and is known as
acetone. Acetone is a top 50 industrial chemical.
 Acetone is a common solvent for nonpolar
substances. (fingernail polish remover)
 To name ketones end the carbon chain in “one”.
Organic Acids (Carboxylic
Acids)
 Carboxylic acids are a group of organic compounds
which have a (COOH) functional group.
 Carboxylic or organic acids are weak acids.
 Examples are : acetic acid, citric acid, benzoic acid,
etc.
 To name these acids use the carbon chain root : and
add the suffix “oic” and the word acid.
Naming Organic Acids
 Draw the structure for the following organic acids:
a) Methanoic acid
b) Ethanoic acid
c) Butanoic acid
d) Propanoic acid
Properties of Organic Acids
 Methanoic acid (formic acid) is the acid in bee and ant
stings.
 Ethanoic acid is acetic acid, found in vinegar
 Small chain organic acids are soluble in water.
 Lactic acid is an organic acid which builds up in body cells.
 Ascorbic acid (Vitamin C) is found in citrus fruits and
tomatoes.
 Bacteria reacts butter into butanoic acid. (rancid butter)
Esters
 Esters are organic compounds formed when an alcohol is
added to an organic acid.
 Esters have distinctive odors.
 Esters have the functional group : (COOC)
 Esters are named by naming the alcohol name first ending in
“yl”, then the acid name is given ending in “oate”.
 When an ester is synthesized from an alcohol and organic
acid, the alcohol gives off the (O) atom , and the acid gives
two (H) atoms to form water.
Esters
 Diagram the reaction of ethanoic acid with
methanol. Name the ester which forms.
Esters
 Draw the structural formula for the following
esters:
a) Ethyl butanoate
b) pentyl ethanoate
Amines
 An amine is an organic
compound which
contains an “amino”
functional group.
 An amino functional
group is NH2
 Amines can contain
several amino
functional groups.
Amines
 Amines are named by
adding the suffix “amine”
to the root name of the
hydrocarbon.
 Amines are also named by
naming the hydrocarbon
ending in “yl” with the
suffix “amine”.
Amines
 Amines are important
biological compounds.
 Amino acids which make
up proteins contain an
amino group along with an
organic acid group.
 Amines are found in DNA.
 Amines are the basis of
several addictive drugs :
nicotine, cocaine, and
amphetamines.
Amino Group
Methamphetamine
Naming Amines
 Draw the structure for the following amines.
a) Butanamine
b) pentylamine
Amides
 Amides are produced when
amines are added to an
organic acid.
 Amides have an amino
group and a carbonyl group
attached to an end carbon.
 Amides are by adding the
suffix “amide” to the end
of the hydrocarbon root.
Amides
 Amides are found in
biological compounds
and in some synthetic
polymers such as
nylon.
Nylon : a polymer with an amide
group in the chain.
Naming Amides
 Draw the structure of
ethanamide.
What is the name of the amide above?
Organic Compound Summary
• The following are the organic compounds we’ve
studied. They are identified by their “functional
group”.
• Hydrocarbons
* Esters
• Alcohols
* Organic Acids
• Ethers
* Amines
• Ketones
* Amides
• Aldehydes
* Halocarbons
Polymers
 Small organic molecules
(monomers) can be reacted
to form long organic
molecules (polymers)
 Example of polymers are :
polyethylene (plastic),
polyvinylchloride (PVC),
nylon, polyester, etc.
 Polymers can be formed by
a condensation reaction
(water is produced)
Polymers
 Polymers can be
formed by an
elimination reaction,
where a simple
molecule (water, etc.)
is removed and a new
compound is formed.
PVC : polyvinyl chloride
polymer
Polymers
 Other polymers include
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Teflon
Polystyrene
Proteins
Lipids
Starches
Polytetrafluoroethene :teflon
monomer
Polymers
 Nylon is a polymer
involving an amide
monomer.
 Nylon was synthesiszed in
the 1930’s and named after
the cities of New York and
London.
 Nylon is produced by
adding an organic acid to
an amine.
 Nylon has many uses.