Chemistry 30
Notes
Hallett 2013
Section 10.1: Petrochemicals in Alberta
The petrochemical industry is a secondary and tertiary industry that takes raw materials (crude
oil and natural gas) and feedstocks (ethane) and converts them into valuable chemicals (figure
1). In Alberta, this is an important economic and social industry, which exports to the rest of
Canada and the world.
Some of the primary petrochemicals in figure 1 have immediate uses, but most have to undergo
further reactions.



Methanol – immediate use as fuel, windshield wiper fluid, gas line antifreeze
Xylene – solvent in many hardware store solutions
Ethene – ripen some fruits, but mostly used in processes to produce polymers
(polyethene)
Complete Practice Questions #1-3
Primary Petrochemicals:
Primary petrochemicals are used to produce the intermediate derivatives (figure 2). Many new
compounds can be made by adding other elements, changing the bonding, or joining small
molecules together.
Complete Practice question #4-8
Ethene and Its Derivatives:
About 5% of our fossil fuels produce petrochemicals. The economic importance relies on the
processing of petrochemicals – look at figure 3 which shows the multiplier effect of the
important ethane (ethylene).
Ethene is produced by cracking ethane that is extracted from natural gas. We used to burn the
ethane in the natural gas without removing it, but now the natural gas that is burned in
industrial settings is likely to have had the ethane, propane and butane extracted as liquids
called natural gas liquids (NGLs) or liquefied petroleum gases (LPGs). The remaining natural gas
is mostly methane.
Table 2 gives the locations of some of the chemical plants that produce products related to
ethane and ethane.
Complete bold terms in notebook, add additional notes from textbook and complete P. 416
questions #1-4.
Section 10.2: Organic Halides and Addition and Substitution Reactions
Organic compounds are divided into two main classes:
-hydrocarbons (contain only carbon and hydrogen atoms) and
-hydrocarbon derivatives (contain carbon, usually hydrogen, and at least one other element –
organic halides, alcohols, carboxylic acids, esters, and polymers).
Read Learning Tip on p. 417
Organic Halides:
Organic halides are organic compounds in which one or more hydrogen atoms have been
replaced by halogen (group 17) atoms. General formula is R—X, where X is a halogen atom.
Examples: chlorofluorocarbons, Teflon.
The functional group is a characteristic arrangement of atoms within a molecule that
determines the most important chemical and physical properties of a class of compounds. The
functional group of organic halides is the halogen atom.
Many organic halides are toxic and carcinogenic:
-DDT (dichlorodiphenyltrichloroethane) pesticide – banned in many countries, but still being
produced (China)
-PCBs (polychlorinated biphenyls) No longer produced, but still in circulation used in electrical
transformers
Solution theory of organic halides:
-are solvents that can dissolve nonpolar hydrocarbons and/or polar hydrocarbons
-may be polar or nonpolar, or may have a relatively nonpolar hydrocarbon end and a polar
halide end
Nomenclature:
IUPAC naming follows the same format as branched-chain hydrocarbons.
Branches are named by shortening the halogen name:
fluoro-, chloro-, bromo-, or iodo- (table 1)
Example: CHCl3 (l) is trichloromethane, C6H5Br (l) is bromobenzene
When drawing the chemical structural formulas, draw the parent chain and add branches at
locations specified in the name. See examples at the bottom of p. 417, which are used to
produce polyvinyl chloride (PVC).
Look at Sample Problem 10.1 and communication examples 1 and 2 – note that the substituents
are in alphabetical order.
Complete Practice Questions #1-5.
Addition Reactions:
Unsaturated hydrocarbons react with small diatomic molecules (hydrogen or bromine) and
usually occur with catalysts. See the examples of hydrogenation on p. 419.
Halides form rapidly with the addition of a hydrogen or halogen to the carbons of a double or
triple bond because they become more stable by achieving an octet of electrons in a
tetrahedral structure of single bonds.
See examples on p. 420: formation of 1,2-dichloroethane (used as a solvent for fats/oils/rubber,
a fumigant, and to produce chloroethene which is used to produce PVC), the addition of
halogens to an alkyne to form an alkene or alkane, addition reactions involving more than one
step, and predicting addition reactions with hydrogen halides.
Look at communication example 3.
Substitution Reactions:
Substitution reactions involve breaking a carbon-hydrogen bond in an alkane or aromatic ring
and replacing the hydrogen atom with another atom or group of atoms. They occur slowly at
room temperature – not enough energy in collisions to break bonds – and electromagnetic
radiation (light) may be necessary to increase the rate.
Example on p. 421 of propane and bromine – a hydrogen atom on the propane molecule is
substituted with a bromine atom, but because it can replace the hydrogen on either the end or
middle carbons, two different products are formed in unequal proportions (not shown in the
reaction equation).
The second example is of a benzene ring, which is a stable structure and also reacts slowly with
halogens, even with light so a catalyst is used. It may also continue reacting until all the
hydrogens are substituted as is the case with alkanes.
Look at Communication Example 4
Complete Practice Questions #6-11.
Complete Investigation 10.1 as a demonstration
Complete bold terms in notebook, add additional notes from textbook and complete P. 424
questions #1-4, 6,7.
Section 10.3: Alcohols and Elimination Reactions
Alcohols:
-have many consumer, commercial, and industrial applications
-have relatively high solubility in water and clean burning properties
-functional group is hydroxyl group (-OH)
-properties:
-high boiling point –OH functional group form hydrogen bonds and are less volatile
-shorter chains are very soluble in water because of their size, polarity, and hydrogen
bonding
-larger alcohols are less soluble in water and are good solvents for non-polar molecules
because the hydrocarbon portion of the long-chain alcohol is non-polar
-used as solvents because they are effective for both polar and nonpolar compounds
-used in the synthesis of other organic compounds
Methanol and Ethanol:
-Two of the most common alcohols: methanol CH3OH (l) and ethanol C2H5OH(l)
-important technological application: gasoline additive to increase octane number, reduce
harmful emissions, and conserve crude oil – often called oxygenators because they provide
oxygen to the combustion reaction, which forms less carbon monoxide in the exhaust – more
complete
-common consumer use of alcohols is antifreeze (figure 2)
-Methanol (wood alcohol) is prepared by:
1. methane reacts catalytically with water to produce carbon monoxide and hydrogen
(see equation on p. 425)
2. Carbon monoxide and hydrogen react at high temperature and pressure in the
presence of a catalyst (see equation on p. 425)
-Methanol is toxic to humans: drinking small amounts or inhaling the vapors for prolonged
periods can lead to blindness or death
-Methanol is added to non-beverage ethanol to denature it – denatured ethanol is toxic.
-Ethanol (grain alcohol) is prepared by:
1. Fermentation of sugars from starch, such as corn and grains - Enzymes produced by
yeast cells act as catalysts in the breakdown of sugar molecules (see equation on p. 426)
-Ethanol is an important synthetic organic chemical – solvent in lacquers, varnishes, perfumes,
and flavourings – is also the raw material in the synthesis of other organic compounds
-Ethanol is added to gasoline in AB as a winter additive for increased vaporization and as a gas
line antifreeze – legislation to include 10% ethanol in gasoline will expand this industry
Complete Practice Questions #1-4
Naming Alcohols:
-Named from the alkane of the parent chain with the number of carbons
-The –e is dropped from the end of the name and is replaced with –ol
-Single bonds between the carbon atoms are communicated by the “an” in the middle of the
name
Look at Sample Problem 10.2 and Communication Example 1
Primary, Secondary, and Tertiary Alcohols:
When writing the molecular formula or condensed structural formula, write the –OH group at
the end.
The position of the –OH group can vary to make their properties different.
Three structural models of alcohols:
1. Primary (1°) alcohols – the carbon atom carrying the –OH group is bonded to one other
carbon atom (butan-1-ol)
2. Secondary (2°) alcohols – the carbon atom carrying the –OH group is bonded to two
other carbon atoms (butan-2-ol)
3. Tertiary (3°) alcohols - the carbon atom carrying the –OH group is bonded to three other
carbon atoms (2-methylpropan-2-ol)
See diagrams on p. 428
When naming alcohols with more than two carbon atoms, the position of the hydroxyl group
must be indicated. Ex. Two isomers of propanol: propan-1-ol is a solvent for lacquers and
waxes, brake fluid; propan-2-ol or isopropanol (meaning the –OH is bonded to the central C) is
sold as rubbing alcohol and is used to manufacture oils, gums, and acetone. Both isomers are
toxic to humans if ingested.
Look at Sample Problem 10.3 and Communication example 2.
Polyalcohols:
-Alcohols that contain more than one hydroxyl group where their names indicate the number
and positions of the hydroxyl groups. Example – ethane-1,2-diol – antifreeze. See example
structures on p. 429.
Look at sample problem 10.4
Cyclic and Aromatic Alcohols:
These compounds can become very complex very quickly so the simplest examples you need to
know are:
-C6H11OH(l) is cyclohexanol
-C6H5OH(s) is phenol (aromatic alcohol) – spring run-off water smell from decaying plant matter
Look at Communication Example 3
Complete Practice questions #5-16
Elimination Reactions:
Elimination reactions are a primary source of alkenes – derived from either alcohols or alkyl
halides. Example ethene as the cornerstone of AB’s petrochemical industry
Producing Ethene by Cracking Ethane:
High temperature cracking of ethane is the preferred technological process for producing
ethene, where molecules of hydrogen are “eliminated” from ethane. See structural equation at
the bottom of p. 431 and build with molecular kits.
Producing Ethene by Elimination Reactions:
-Ethene was first discovered by heating ethanol in the presence of a catalyst sulfuric acid
-other catalysts were discovered for the reaction such as aluminium oxide and phosphoric acid
(fig. 5)
-Elimination reactions involves eliminating atoms or groups of atoms from adjacent carbon
atoms
-in the case of ethanol to form ethene and water, a hydrogen atom and a hydroxyl group are
eliminated forming water as a by-product – this is called dehydration because of the removal of
water from the alcohol (see structural equation on p. 432 and build with model kits)
-dehydrohalogenation (removal of hydrogen and halogen atoms) can also produce ethene by
reacting chloroethane with potassium hydroxide, in which a hydrogen atom and a halogen
atom are eliminated from the alkyl halide to produce the alkene plus a halide ion and a water
molecule (see structural formula on p. 432 and build with model kits)
-there are other elimination reactions and other ways to synthesize ethene and other alkenes,
but the above examples are the best choices for the laboratory and industrially cracking is the
best method
Look at communication example 4 and 5
Complete Practice Questions #18-21
Complete bold terms in notebook, add additional notes from textbook and complete P. 435
questions #1-9, 11.
Section 10.4: Carboxylic Acids, Esters, and Esterification Reactions
Carboxylic Acids:
-contain the carboxyl group (-COOH) which includes both the carbonyl and hydroxyl functional
groups (see diagram and Learning tip on p. 436)
-the carboxyl group is always at the end of the carbon chain or branch
-occur naturally in citrus fruits, crabapples, and other foods with a sour tangy taste and have
distinctive odors (figure 1)
-are polar and form hydrogen bonds with each other and water
-exhibit the same solubility behavior as alcohols – smaller molecules are soluble, where the
larger molecules are insoluble
-have properties of acids – litmus test, etc.
-smaller molecules are liquids at room temperature, dicarboxylic acids (even small ones) are
solids at room temperature and the large molecules are solids at room temperature
Naming:
-named by replacing the –e ending of the corresponding alkane name with –oic acid.
Example methanoic acid HCOOH, commonly called formic acid (figure 2), which is used in
recycling rubber
Example ethanoic acid CH3COOH (l), commonly called acetic acid, makes vinegar taste sour –
wine and cider vinegar are produced naturally from fermented fruit juices to form alcohol, to
ethanoic acid (see formation on p 437)
Example oxalic acid has two carboxyl groups bonded together – is in rhubarb, grapes and is in
rust removers and copper/brass cleaners (See structural formulas on p. 437)
Due to the extra hydrogen bonding all three of these examples are solids at room temperature
and notice that multiple hydrogen bonding is possible, which increases the melting and boiling
points and solubility in water.
Complete Lab Exercise 10.B
Look at sample problem 10.5 and communication example 1
Complete Practice Questions #1-2
Esterification Reactions:
In a condensation reaction, a carboxylic acid combines with another reactant, forming two
products – an organic compound and a compound such as water. Example – a carboxylic acid
can react with an alcohol, forming an ester and water. This type of condensation reaction is an
esterification reaction. See chemical structure of equation on p. 438.
Esters:
-has functional group –COO-similar to an acid except the H atom of the carboxyl group has been replaced by a hydrocarbon
branch
-occur naturally as odours of fruits and flowers
-are added to foods to enhance aroma, are found in cosmetics, perfumes, fibers, and solvents
-Artificial flavourings are made by mixing synthetic esters to give the approximate smell of the
natural substance such as raspberry or banana (see Table 2)
-fruit flavours – organic acids are usually added
Naming and Preparing Esters:
-are formed from a reaction of a carboxylic acid and an alcohol
-name has two parts:
1. the first part is the name of the alkyl group from the alcohol used in the
esterification reaction
2. the second part comes from the acid – the ending of the acid name is changed
from –oic acid to oate
Example: the reaction of ethanol and butanoic acid forms ethyl butanoate (banana odour) – a
strong catalyst (H2SO4(aq)) and heat is used to increase the rate of the reaction (see structural
diagram on p.439)
-general formula is RCOOR – RCO- comes from the carboxylic acid and –OR comes from the
alcohol
*Note that for an ester, the acid is the first part of the formula, but the second part of its name
(see example on p. 440)
Look at Sample Problem 10.6, 10.7, and communication example 2
Complete Practice Questions #3-7
Complete Investigation 10.4
Complete bold terms in notebook, add additional notes from textbook and complete P. 443
questions #1-8.
Section 10.5: Polymerization Reactions – Monomers and Polymers
-Polymers are large molecules made by linking together many smaller molecules, called
monomers
-different types of small molecules form links through addition or condensation reactions
-different properties can be manipulated such as strength, flexibility, density, transparency, and
stability
- natural polymers are amber from tree sap, rubber and cotton (plant polymers), wool and silk
(animal polymers), proteins and carbohydrates (in us)
-synthetic polymers are plastics
-Polymerization is the formation of polymers from the reaction of monomer subunits – have
molar masses up to millions of grams per mole
Addition Polymers:
-many plastics are produced by the polymerization of alkenes
Example: polyethene (polyethylene) is made by polymerizing ethene molecules – addition
polymerization - this is used to make wire insulation, milk bottles, (figure 1) and fridge dishes
-Addition polymers are formed when monomer units join each other in a process that involves
the rearranging of electrons in double or triple bonds in the monomer – the polymer is the only
product
See structural equations on p. 445
-Monomers form dimers (from two monomers) and trimers (from three monomers) and
continue reacting to form polymers
Polypropene:
-commonly called polypropylene
-propene undergoes addition polymerization
-uses: polypropylene rope (figure 3), carpet
-see structural reaction on p. 446: similar to polyethene, propene molecule is considered an
ethene with a methyl group in place of hydrogen, polymer formed contains a long carbon chain
with methyl groups attached to every other carbon
Polyvinyl Chloride:
-commonly called PVC
-addition polymer of chloroethene (vinyl chloride)
-uses: insulation for electrical wires, coating on raincoats and upholstery (fig 4)
-see structural reaction on p. 447
Polystyrene:
-benzene ring attached to ethene = vinyl benzene, commonly called styrene
-addition polymer of styrene is polystyrene
-uses: cups and containers – look for recycle symbol with a 6 and PS
-see structural reaction on p. 447
Teflon:
-common name for an addition polymer with nonstick properties used in cookware
-tetrafluoroethene is the monomer used to synthesize Teflon
-the absence of carbon-hydrogen bonds and the presence of very strong carbon fluorine
bonds makes it very unreactive – allows it to be in contact with foods at high temperatures
without sticking
-controversy about its safety
-see structural reaction on p. 447
Complete Practice Questions #1-7
Condensation Polymers:
Condensation polymerization reactions involve the formation of a small molecule (H2O, NH3,
HCl) from the functional groups of two different monomer molecules
-monomer molecules bond at the site where atoms are removed from their functional groups
-to form a condensation polymer, the monomer molecules must each have at least two
functional groups, one on each end
Comparing Natural with Synthetic Polymers:
-a synthetic compound that has a similar chemical structure to a naturally occurring substance
is called a structural analog
-example: nylon is a structural analog of protein, but not a functional analog (fig 6)
-functional analogs are synthetic compounds that perform the same function as a naturally
occurring substance but do not necessarily have similarities in chemical structure
-example: synthetic sweetners are functional analogs of sugar
-many synthetic condensation polymers are structural analogs to natural polymers found in
foods: lipids (fats and oils), proteins, and carbohydrates
Lipids and Polyesters:
-lipids (fats and oils) are formed by esterification reactions between glycerol and fatty acids:
-since glycerol has three hydroxyl groups, three molecules of fatty acid can react with
each glycerol molecule to form a tri-ester
-this reaction is a condensation reaction that is not a polymerization reaction: the
largest molecule formed is a tri-ester
-Look at the structural reaction on p. 450
Complete Practice questions #9-11
Polyesters:
-polyesters are many esters joined in a long chain through a repeated esterification reaction
-a dicarboxylic acid (acid with a carboxyl group at each end) and a diol (alcohol with a hydroxyl
group at each end) are needed
-see the structural, symbol, and Dacron examples on p. 451
Complete Practice Questions #12-14
Proteins:
-ten billion different proteins in living organisms that are constructed from about 20 amino
acids
-reaction of the carboxyl group and the amine (-NH2) group, amino acids polymerize into
peptides (short chains of amino acids) or proteins (long chains of amino acids)
Example: condensation reaction of the amino acids glycine and alanine forms a dipeptide
-condensation polymerization produces a protein – thousands of monomers long
-dipeptide reacts with itself or with more glycine and/or alanine
-other amino acids may be present to produce more complex peptides
-polypeptides produced by polymerization is a protein with peptide (-CONH-) linkages
-see the general equation for the formation of a protein from amino acids on p. 453
Nylon:
-synthetic condensation polymer that forms by the reaction of a carboxyl group (-COOH) with a
–NH2 group with amide linkages (-CONH-)
-polymers with amide linkages are called polyamides
-amide linkages in proteins are called peptide linkages and the polymers are called
polypeptides
-see the example of nylon 6,6 formation on p. 453
-uses in WWII: parachutes, ropes, cords, shoelaces
-CONH group makes it strong because the chains line up parallel to one another and the –CONH
groups form hydrogen bonds with the adjacent chains
- see diagram on p. 454
Kevlar:
-stronger than steel, heat resistant, lightweight
-uses: aircraft, sports equipment, protective clothing, bulletproof vests
-polymer chains form a strong network of hydrogen bonds holding adjacent chains together in a
sheet-like structure, which are stacked together to form extraordinarily strong fibres
-see diagram on p. 454
Complete Practice Questions #15-17
Carbohydrates and Cellulose Acetate:
-sugar molecules have the general formula Cx(H2O)y
-sugar undergoes a condensation polymerization reaction – a water molecule is formed and the
monomers join together to form a larger molecule
Example: glucose and fructose can form sucrose (table sugar) and water (see diagram)
-simple sugar monomers are monosaccharides, dimers are disaccharides, and polymers are
polysaccharides
-starch and cellulose both consist of large glucose chains
Starch for Energy; Cellulose for Support:
-Starchy foods provide energy and are energy storage in plants
-starches are polymers of glucose, either branched or unbranched, and are polysaccharides
-in our digestive tracks we have enzymes that break down starch, but there is no enzyme for
breaking down cellulose
-cellulose provides structure and support for plants (wood, cotton, hemp)
-cellulose is indigestible, which is why fruits, grains and vegetables are sources of fibre
-cellulose is a straight chain, rigid polysaccharide with glucose-glucose linkages that are
different
-when glucose forms are ring structure, the functional groups attached to the ring are fixed in a
certain orientation above or below the ring – our enzymes are specific to the orientation of
functional groups and cannot break the linkages, but herbivores have specially developed
stomachs and intestines that hold bacteria or protozoa to break down cellulose
-starch: glucose monomers are added at angles that lead to a helical structure which is
maintained by hydrogen bonds between –OH groups on the same polymer chain (figure 11a)
-single chains are small enough to be soluble in water allowing them to be mobile
-in cellulose, glucose monomers are added to produce linear polymer chains that align side by
side causing hydrogen bonding (figure 11b) which cause a rigid layered sheets of cellulose
making it strong and insoluble in water
Complete Practice Questions #18-23
Cellulose Acetates – Structural Analogs of Polysaccharides:
-biopolymers are modified natural polymers
Example: cellulose triacetate – cellulose is modified by reacting it with acetic acid and acetic
anhydride with sulfuric acid as a catalyst (see diagram on p. 458). Uses: fabrics in textured knits,
sportswear
Complete bold terms in notebook, add additional notes from textbook and complete P. 460
questions #1-14.