UNIT 2 – ORGANIC CHEMISTRY
- Introducing Organic Compounds
o An organic compound is when C atoms are nearly always bonded to each other, to H
atoms, and sometimes to atoms of a few specific elements
 Usually O, N, S, or P
 Exceptions: carbonates (CO3-2), cyanides (CN-), carbides (C2-2), and oxides
of carbon (CO2, CO)
o Classified as inorganic compounds
o Isomers:
 Molecules that have the same molecular formula but with their atoms in a
different arrangement
 2 types
 Constitutional isomers
o Molecules that have the same molecular formula but their
atoms are bonded together in a different sequence
 Also referred to as a structural isomer
 Ex. 6 C + 14 H can form 5 isomers
o 10 C + 22 H can form 25 isomers
o 20 C + 42 H can form 366319 isomers


Can have ring structures
Stereoisomers
o Molecules that have the same molecular formula and their
atoms are bonded together in the same sequence
o Rigidity of the structure of atoms around a double bond help
determine the type of isomer
o 2 types:
 Diastereomers

Only form when each C atom involved in the
double bond has different types of atoms or
groups of atoms bonded to it
o When two identical atoms/groups are
on the same side of the double bond
 Called cis isomer
o When two identical atoms/groups are
on the opposite side of the double bond
 Called trans isomer
o

Triple bonds do not form diastereomers
but can form constitutional isomers
Enantiomers
 Are mirror images of each other around a single
C atom
o
Must have 4 different atoms around the
C
-
Hydrocarbons
o Hydrocarbons are organic compounds that contain only C and H atoms
 Ex. fossil fuels, gasoline, and natural gas
o Types:
 Alkanes
 Contain only single covalent bonds
 Are saturated hydrocarbons because does not contain any double or
triple bonds
o Also saturated because each C is bonded to as many other
atoms possible
 General formula CnH2n+2
o The straight alkane chains can have branches in which 1 C is
bonded to more than 2 other carbon atoms
 The branches are referred to as substituent/side groups
 All side chain names end in –yl; referred to as
alkyl groups
Number of C
1
2
3
4
5
6
7
8
9
10
Prefix Number
mono
di
tri
tetra
penta
hexa
hepta
octa
nona
deca

Root Name
methethpropbutpenthexheptoctnondec-
Side Chain Name
methyl
ethyl
propyl
Butyl
pentyl
hexyl
Naming:
o Identify the root
 Identify longest continuous chain
 Find the root for the number of C atoms in the chain
 Start the numbering closest to the side chains
because they need to be written with the
lowest possible number to get to them
o Identify the suffix (-ane)
o Identify the prefix
 It indicates position, number, and type of side group on
the main chain
 Identify the number of C atoms in each side
group


o
Determine the name of each side group
If more than 1 type of side group write in
alphabetical order
 Determine position of each side group
 Before the name of each side group place the
number of the C atom to which it is attached on
the main chain
o Use hyphens to separate to separate
number and words, use a coma to
separate numbers
 Use a prefix to identify how many of each type
of side chain are present if more than one of
the same
o i.e. di, tri, etc.
Name the compound
 (# of location)-branch name (parent chain name)

Exception: if the side chains have the same numbers no matter the
direction (i.e. 4, 5 or 5, 4) the compound must be numbered in the
direction that gives the side chain that comes first alphabetically the
lowest number
o Structural isomers for alkyl groups

Models for drawing:
o Empirical formula
 C4H10
o Expanded molecular formula
 Use brackets to identify location of side chains
 CH3CH(CH3)CH2CH3
o Structural formula

o
Condensed Formula
o
Line Structural Formula
 Each end counts as a C atom
Examples:
o Name the following
o
Draw the following
 2, 2 – dimethyl-3-propyloctane


2, 3, 3 – triethylpentane

If you have a cyclic hydrocarbon the prefix is cycloo Ex. cyclobutane

If a longer chain exists attached to the cyclo structure then the cyclo
structure becomes the alkyl group

Physical properties
o Are non-polar and not soluble in water (recall: like dissolve like)
 Are soluble in benzene and other non-polar solvents
o Small alkanes are usually gases, medium length alkanes are
usually liquids, and large alkanes are waxy solids
o B.p. increases as straight chain increases
Alkenes
 Have a least 1 double bond in the parent chain
 All alkenes consist of at least 2 C atoms
 Can bond to more atoms than are already present due to double bond
 Since C atoms are not bonded to maximum number of atoms possible
they are said to be unsaturated hydrocarbons
 General formula: CnH2n

Naming:
o Identify the longest chain that has the double bond
o Number the main chain starting closest to the double bond
o If the alkene contains 4 or more carbons you must give the
position of the double bond by giving the number of the C atom
that comes before it (suffix –ene)
 Ex. but-2-ene
o Name the side groups the same

Examples:
o Name the following
o

Draw the following
 4-ethyl-2,5-dimethyloct-3-ene
Physical properties
o Are non-polar
o The first 3 alkenes are gases (ethane, propene, butane)
 The larger sizes are liquids
o For smaller size in C atoms they have lower b.p. than alkanes
 Also for same alkene structures but different location of
double bonds b.p. changes

Alkynes
 Have at least 1 triple bond
 Are unsaturated hydrocarbons
 General formula: CnH2n-2
 Naming:
o Same rules as alkenes, except suffix is –yne
 Examples:
o Name the following
o
Draw the following
 2,5,6-triethylnon-3-yne


Physical properties
o Are non-polar
o First few alkynes exist as gases
o B.p. is larger than alkenes and alkanes
 Due to linear structure and nature of triple bond causes
it to attract 1 another more strongly
 Takes more energy to overcome these
attractive forces
Aromatic hydrocarbons
 Have a low hydrogen to carbon ratio and unusual stability
o Due to the presence of multiple bonds
 All based on the presence of a benzene ring
o i.e. C6H6


Aliphatic compounds form chains, not rings
The benzene is a resonance hybrid because the double bonds can rotate
o
The C-C bonds all have the same properties
 Use a circle in the benzene ring to represent changing
double bonds
 i.e.

The electrons in the bond are considered to be
delocalized electrons
 The double bonds are considered to be
conjugated double bonds
o Very stable because electrons are not
readily available
 A benzene ring as a side chain is
called phenyl

Naming:
o If the benzene ring is the longest chain the root name is
benzene

Examples:
o Name the following
o
Another way to name aromatic side chains

-
Physical properties
o Benzene properties
 Benzene is a liquid at room temperature
 B.p. is similar to aliphatic hydrocarbons that have the
same number of C atoms
 Have a strong odour
Hydrocarbon derivatives
o Classify compounds according to their functional groups
 Is a special arrangement of atoms responsible for chemical behaviour of the
molecule
 Hydrocarbon derivatives can form when 1 or more functional groups are
attached to a hydrocarbon
o
Alcohols
 Contains a hydroxyl functional group; -OH
 Naming
 Identify longest chain including hydroxyl group and use the name of the
parent alkane as a starting point
o Hydroxyl groups need to have lowest number and give number
location in the name
 End in –ol (drop the –e from the alkane, ex. methanol)
 If more than 1 OH give prefix (di, tri, tetra, etc.)
 If double or triple bond is present, they take precedence over functional
group and OH gets named as a side chain, i.e. hydroxyl
 Examples:
 Name the following

Draw the following
o 2, 3-diethylcycloheaxanol

o
Physical Properties
 Hydroxyl group is very polar
o However as C chain grows usually becomes non-polar
 Hydroxyl group also allows the alcohol to hydrogen bond with one
another
 B.p. is higher than alkane
 Straight chain alcohols fewer than 12 C are liquid
Haloalkanes
 Contains at least 1 halogen atom
 Naming:
 Identify longest chain and lowest number of side chains
 Alphabetical order
o Cl, chloro; F, fluoro; Br, bromo; I; iodo
 Used as a prefix
 Examples:
 Name the following


Draw the following
o 2, 4-dibromo-3-chlorohexane
Physical properties
 Only small haloalkanes are slightly soluble in water
 i.e. halomethanes
 b.p. of haloalkanes is much greater than similar size hydrocarbon chains
o
Aldehydes

Contain a carbonyl functional group,

Aldehydes contain a formyl group,
 Always found at the end of the chain
Naming:
 Identify longest chain and stat at the formyl group
 Name the parent alkane, drop the –e and the suffix now becomes –al;
ex. methanal
o Also known as formaldehyde
 When mixed with water it is used to preserve organisms
 Solution is called formalin
Examples:
 Name the following




Draw the following
o 2-chloroethanal
Physical properties
 The carbonyl group is very polar
 Cannot H bond with 1 another but can H bond with water
 Strength of attraction not as good as alcohols
 B.p. is lower than alcohol with same number of C atoms
 Methanal is a gas, ethanal can be a volatile liquid, 15 C chains or longer
are waxy solids
o 1-4 C chains are soluble, 5-7 C chains are slightly soluble, longer
than 7 are insoluble
 Short chain aldehydes have a very pungent odour
 When it gets larger it becomes more pleasant
o
Ketones
 Acetone is a common ketone, propanone, used in nail polish removal
 Ketones are an by product of fatty acid metabolism
 Contains a carbonyl group bonded to 2 C toms



 Where R is any C atom
Smallest ketone must have 3 carbons
Naming:
 Identify the longest chain including carbonyl group
 Drop the –e from the parent alkane to –one
 Start numbering closest to carbonyl carbon
o Give location of carbonyl carbon in name for carbon chains
greater than 4
Examples:
 Name the following

Draw the following
o 4, 4-diethylhexane-2, 3-dione
o
2-phenyl-5-t-butyldecan-3,4, 6-trione

o
Physical properties
 Again carbonyl group is very polar but compounds cannot H bond with
one another
o Can H bond with water molecules
 B.p. and solubility is similar to aldehydes
 Carbon chains 15 and larger are waxy solids, all smaller ketones are
liquids
Carboxylic Acids
 Acetic acid which is found in vinegar and citric acid which is found in oranges are
examples of carboxylic acids
 Contains a carboxyl group ( -COOH )





Is a carbonyl group with a hydroxide attached
o Ex. methanoic acid (or formic acid)
Are weak acids
 -COOH (aq) ↔ -COO- (aq) + H+(aq)
Must always be on the end of the chain
 Always the starting position
Naming
 Identify the longest chain starting at carboxyl end
 Drop the –e from the parent alkane and add –oic acid
Examples:
 Name the following


o
Draw the following
o Pentandioic acid
Physical properties
 The C=O and OH are very polar and allows the compound to form H
bonds with one another
 B.p. is higher than any functional group discussed so far
 Short chains are liquids and longer are waxy
 Small chains are soluble in water due to the carboxyl group
 Can conduct electricity because it is a weak acid
Esters
 General formula, RCOOR
 Give off very distinct aromas, ex. flavoured chewing gum
 Formed by the combination of a carboxylic acid and an alcohol


Naming
 The root name is taken from the carboxylic acid side
o Drop the –oic acid and add -oate
 The alcohol side is named first like a side chain without a number
position
 Start to count from the carbonyl group
Examples
 Name the following


o
Draw the following
o Ethyl 2 –cyclobutylpropanoate
Physical properties
 The C=O group makes them somewhat polar but with no OH group they
can nor form H bonds with one another
 B.p. is lower than smear alcohols and carboxylic acids
 Small chains are liquids and large ones are waxy solids
 Esters with 4 or less C atoms are soluble in water
Ethers
 Was, and in some areas still is used as an anaesthetic
 Also used as a starter for diesel engines in cold weather, aerosol
propellant, solvent, and plasticiser
o Helps gasoline to burn cleaner
 An oxygen atom is single bonded to two carbon atoms, R-O-R’
 Naming
 Identify the longest chain and name like the parent alkane
 Start numbering close to oxygen atom
 The shorter chain on the other side of the oxygen is considered an
alkoxy group
o Drop the –ane from the parent alkane and add –oxy
 Location is given by C atom from longest chain that
touches O atom
 Smaller chain is named first
 Examples:
 Name the following


o
Draw the following
o 2-phenoxyheptane
Physical properties
 The bond angle formed by C-O-C (110◦) makes it slightly polar
 Cannot form H bonds with one another
 Ethers with 2 or 3 C atoms are gases, larger are liquids
 Can form H bonds with water
o C atom less than 6 are slightly soluble
Amines
 Are basic molecules that are neutralized by acids into a salt form
 Can be used as corrosive inhibitors, antioxidants in roofing asphalt, flotation
agents in mining
 Adrenaline is a biological source of amines
 Contain a N atom bonded to at least 1 C (although it can bond to 3)
 Primary amines have 1 C, secondary amines have 2 C, tertiary amines
have 3 C atoms
 Naming
 Identify the longest chain bonded to the N
o Start to count close to the N
 Drop the –e from the parent alkane and add amine
 Provide location number if necessary
 For secondary and tertiary amines name as alkyl groups and their
location is given by the letter N
o Order alphabetically
 Examples:
 Name the following

Draw the following
o Hexan-1, 4-diamine
o

o
N-phenylbutan-1-amine
Physical properties
 The N-H bonds in primary and secondary are very polar
o Can H bond with themselves but tertiary cannot
 Primary and secondary have high b.p. compared to similar ethers and
alkanes
o Also higher b.p. then tertiary amines
 All amines can H bond with water
o Smaller amines are very soluble in water
Amides
 Found in pain reliever medication and organic solvents used in industry
 Also found in polymers such as nylon
 General formula



Primary amides have 2 H’s bonded to N, secondary has 1 H, and tertiary has only
alkyl groups bonded to the N
Are formed by the addition of a carboxylic acid to ammonia (or a primary or
secondary amine)
 i.e.
Naming
 Identify the longest chain that has the carbonyl group
o Drop the –e from the parent alkane and add –amide
 Start the count from the carbonyl group


Name the side chains on the N as alkyl groups and give the location
using the letter N
Examples:
 Name the following


o
-
Draw the following
o N-ethyl-N-propyl-2-methylbutanamide
Physical properties
 Have a polar carbonyl group and primary/secondary amides have at
least one –NH group
o Can form strong H bonds among themselves
 Have the largest b.p. than similar hydrocarbons
 Small amides are very soluble in water
Overall polarity from greatest to least
 Amide > acid > alcohol > ketone ≈ aldehydes > amine > ester > ether > alkane
Types of Organic Reactions
o Addition reactions
 Alkenes and alkynes undergo this reaction due to double or triple bonds
 Small molecule is added to it
 H2O, H2, HX, or X2 (where X = F, Br, Cl, or I)
 Forms 1 major product or 2 products that are isomers of each other

It is possible to determine the major product of a reaction using Markovnikov’s
rule
 The H atom of the small molecule will attach to the C of the double
bond that is already bonded to the most H atoms
o
o
In some reactions we use Pt or Pd as catalysts
Elimination reactions
 Atoms are removed and a double bond forms between 2 C atoms from which
the atoms were removed
 i.e. reverse of addition reaction
 1 reactant usually loses 2 atoms and 2 products are formed
 Heat is usually used as catalyst and sulfuric acid is used for alcohols
(H2SO4)

o
Substitution reactions
 A H atom or functional group is replaced by a different functional group
 2 compounds react to form 2 different compounds
 Alcohols and haloalkanes commonly undergo substitution reactions


o
For larger molecules the H atom to be removed will come from the C atom with
the most C-C bonds
Alkanes can also undergo the reaction in the presence of ultraviolet light by
reacting with Cl2 or Br2
Aromatic hydrocarbons can also react with Cl2 and Br2 in the presence of FeBr3
catalyst
Condensation reactions
 A reaction in which 2 large molecules combine and form 1 larger molecule and a
very small molecule; usually water
 Form large biomolecules such as: proteins, carbohydrates, fats, and DNA
 Recall amino acids are building blocks of proteins
o
Esterification reactions
 Special type of condensation reaction in which carboxylic acids react with
alcohol to form an ester and water
 Sulfuric acid is used as a catalyst
o Ex. Aspirin and artificial flavours
o
Hydrolysis reactions
 Essentially the reverse of a condensation reaction
 Compounds formed by condensation reactions can be broken down by
hydrolysis
 The OH of the water group is added to 1 side of a bond and the H atom of the
water is added to the other side to break the bond
o
Oxidation reactions
 A reaction in which a C atom forms more bonds to O or fewer bonds to H
 Oxidation that involves the formation of C=O bonds may also be classified as an
elimination reaction
 i.e. alcohols can be oxidized to produce aldehydes and ketones
 Occurs when an organic compound reacts with an oxidizing agent
 Ex. potassium permanganate KMnO4, acidified potassium dichromate
K2Cr2O7, and ozone O3
 Symbol [O] is used to symbolize oxidizing agent
o
Reduction reaction
 A reaction in which a C atom forms fewer bonds to O and more bonds to H
 Often C=O or C=C bonds are reduced to a single bond
 Also considered an addition reaction
 Aldehydes, ketones, and carboxylic acids can be reduced to becomes alcohols
 Also alkenes and alkynes by adding H2
 Common reducing agents: lithium aluminum hydride LiAlH4, and hydrogen has
over platinum catalyst H2/Pt
 The symbol [H] is used to symbolize reducing agent
o
-
Combustion reaction
 A hydrocarbon reacts with oxygen to produce the oxides of elements that make
up the compound
 Types:
o Complete combustion
 Produces CO2, water vapour and energy
o Incomplete combustion
 When insufficient O is present
 Product now has CO and soot
 Soot is tiny pieces of unburned C
 Cannot balance
Polymers
o Long molecule that is made by linking together many smaller molecules called
monomers
 i.e. like a long chain of paper clips linked together
 Each paper clip is equivalent to a monomer
o Can be synthetic or natural
o Some can be molded and heated into specific shapes and forms to make plastics
 Plastics are all synthetic
 Other examples are adhesives, chewing gum, polystyrene
o The name has the prefix poly- before the name of the monomer
 Common names are sometimes used over the proper name
 Ex.
o Polyethylene where the monomer is ethane
 Used to make plastic bags, containers, and food wrap
o Polyvinyl chloride where the monomer is chloroethene
 Also called PVC
 Can be used for adhesives and auto parts
o Natural polymers are used to make fabrics such as cotton, linen, and wool
o Polymers are found by:
 Addition polymerization
 A reaction in which alkene monomers are joined through multiple
addition reactions to form a polymer
o Characterized by a reduction in number of double bonds

o
o
Condensation polymerization
 Monomers are combined through multiple condensation reactions
o Water is usually produced
 For the reaction to occur each monomer must have 2 functional groups
o Usually 1 at each end
Industries usually use petroleum to make polymers
 Organic reactions are used to convert the hydrocarbons into petrochemicals
Natural polymers are found in almost every living system
 Includes:
 Polysaccharides
o Polymers comprising of sugar monomers
 Ex. cellulose, starch
 Proteins
o Made up of amino acids
 DNA
o Composed of repeating units called nucleotides
 Contains a sugar, phosphate group, and a cyclic organic
molecule containing N