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ORGANIC CHEMISTRY Chapter 25
Vacation packet #2
Mrs. Brunet
Our extent of Organic Chemistry for the AP test is pretty limited…yeah! As part of the
Descriptive Chemistry, you need to know: “3. Introduction to organic chemistry: hydrocarbons and
functional groups (structure, nomenclature, chemical properties)”
Organic Chemistry is the study of carbon containing compounds.
Before 1828 the vital force theory, which stated that organic
compounds could be extracted only from living, or once living
organisms, was widely accepted. Only to be dashed by Friedrich
Wohler’s synthesis of urea (not urine but a component of it), an
organic compound from the heating of an organic compound from
the heating of an inorganic compound. Check out the organic
chemist’s version of our favorite periodic table
Carbon exists as an element in three different forms, called
allotropes: graphite, pencil “leads”; diamond, a girl’s best friend; and
buckministerfullerene, or the bucky ball (looks like a hollow soccer
ball). [25.1]
The basics of our expected o-chem knowledge for the AP exam
(chemmy bear link = study cards):
http://www.chemmybear.com/apch23sc.pdf

Nomenclature

Functional groups

Properties of compounds

How to draw various types of isomers
Nomenclature of organic compounds is based upon the structure of
the molecule

Straight chain of carbons (normal or n-)

Branched chains

Cyclic molecules, rings like benzene
ORGANIC CHEMISTRY Chapter 25
Vacation packet #2
Mrs. Brunet
Let’s start with the basics and we will build on those. I know this stuff looks big and bad but
it’s really quite simple…honest engine. Don’t be fooled by the IUPAC logo, it just stands for
International Union of Pure and Applied Chemistry. I suggest you make your own clever
acronym for this stuff. Check out section 25.2-25.3, your book has a good plan for naming
hydrocarbons.
First of all the basis of the names is on the number of carbon atoms that make up the
structure. The last name consists of one of the following roots:
# of
carbons
in the
longest
chain
1
2
3
4
5
6
7
8
9
10
Root
MethEthPropButPentHexHeptOctNonDec-
Second is the suffix of the last name and that depends upon the type of bonds between the
carbons.
One of more of
these types
All single bonds
At least one double
bond
At least one triple
bond
Suffix of
name
-ane
-ene
-yne
ORGANIC CHEMISTRY Chapter 25
Vacation packet #2
Mrs. Brunet
Let’s start with alkanes which are single (sigma,
this is a little ahead for us but every single
covalent bond is called a sigma bond) bonded
molecules. These have the general formula CnH2n+2.
Alkanes containing fewer than 5 carbons are gases
(propane, the outdoor barbeque fuel) 5-15 are
liquids (like kerosene and gasoline), and >16 are
solids (paraffin or wax). Alkanes are said to be
saturated because they have all single bonds.
This molecule can be drawn structurally (above) or
made with 3D models or written condensed: CH3CH3 This is ethane because there are two
carbons in the longest chain and only single bonding.
Many times hydrogens are omitted to make the structural formula simpler, or condensed. This
can be useful when the longer chains are being used:
C—C—C—C also written as CH3CH2CH2CH3 or
where each end represents a carbon
Four carbons in a straight chain, this is n-butane. The n stands for normal or straight chain.
The name here changes even though there are still four carbons. Branched hydrocarbons
(hydrogen and carbon compounds) are named based upon the longest chain. Anyway, you look at
this molecule it has three continuous carbons thus propane. But we must name the branched
part. Since the branched part is one carbon atom, the name still comes from the prefixes,
meth-, but we substitute the suffix –yl and add it to the beginning of the name for the longest
chain METHYL PROPANE or more commonly, isobutane.
ORGANIC CHEMISTRY Chapter 25
Vacation packet #2
Mrs. Brunet
For the longer chains the placement of the side group is denoted by numbering. The longest
carbon chain is numbered with the lowest numbering associated with the side groups.
The name for this molecule is 2-methylpentane. The other option 4-methylpentane would be
incorrect because 2 is a lower value. The longest chain is five and all single bonds with a side
group off of the second carbon.
The rules for naming alkanes are condensed in a table on pg. 1068 and good examples on pg.
1069. Look at exercises 25.1 on pg. 1071, and 25.2 on pg. 1072. Check out a few more examples
at http://www.sciencegeek.net/APchemistry/APtaters/alkanes.htm
You should now be ready to do homework #1 (in dropbox).
CYCLOALKANES
Arranged in a cyclic pattern, these occur with the general formula of CnH2n The names use the
same parent name, adding the prefix “cyclo” to describe the shapes. For naming rules and
practice see science geek.com: http://www.sciencegeek.net/APchemistry/APtat
ers/cycloalkanes.htm
UNSATURATED HYDROCARBONS
http://www.organicchemistry.com/tag/unsaturated-carbon/
ALKENES [25.4]
ORGANIC CHEMISTRY Chapter 25
Vacation packet #2
Mrs. Brunet
-unsaturated hydrocarbons occurring in CnH2n but are not cyclic. These are said to be
unsaturated because the double bond can open up and become saturated with more hydrogen or
other substituents.
-naming:

Use longest chain containing a double
o Over 10 million tons/year
bond, can by cyclic also
produced
o Used in refining of petroleum
2-Butene

Also for production of plastics,
antifreeze, synthetic fibers, and
solvents
Ethylene
IUPAC name

Use the lowest number for the first
IUPAC name[hide]
double-bonded carbon


Suffix of hydrocarbon changes to –
Ethene
ene to represent the double bond

Ethene (ethylene)


ORGANIC CHEMISTRY Chapter 25
Vacation packet #2
Mrs. Brunet
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




Propene (propylene) PPE
o Plastics and synthetic fibers
IUPAC name[hide]
Propene
Propene
ALKYNES more from science geek:
ardbanks/organic/nomenclature/aromaticno
http://www.sciencegeek.net/APchemistry/or
menclature1.htm
ganic/alkene_alkyne.shtml

General formula of CnH2n-2 , very
reactive, unsaturated

Contains at least one triple bond

Suffix changes to –yne
*Note: If there are two or more triple
bonds, they are called alkadiynes (two triple
bonds), alkatriynes (three triple bonds), and
so on, NOT alkynes. This also applies to the
alkenes.
HW 2 p. 1110 #6,8,12,22,24
AROMATIC HYDROCARBONS
http://chemistry.boisestate.edu/people/rich
Benzene
ORGANIC CHEMISTRY Chapter 25
Vacation packet #2
Mrs. Brunet

IUPAC name[hide]
Benzene

Cyclic and unsaturated

C6H6 is the most simple, benzene
Aromatic compounds are generally
derived from benzene

Most have distinctive odors, but not
all

Used in plastics, fibers, explosives,
paint, and petroleum
FUNCTIONAL GROUPS p1083
HALOGEN DERIVATIVES

Compound has a halogen atom(s) substituted for a hydrogen atom(s)

Halogen names are treated like prefixes to the parent name

F=fluoro-; Cl=cloro-; Br=bromo-; I=iodo-
Chloroform
IUPAC name[hide]
Chloroform
Systematic name[hide]
Trichloromethane
Other names[hide]
Formyl trichloride, Methane trichloride, Methyl trichloride,
Methenyl trichloride, TCM, Freon 20, R-20, UN 1888

ORGANIC CHEMISTRY Chapter 25
Vacation packet #2
Mrs. Brunet
HALOHYDROCARBONS (sounds like a video game, huh?)

Replacement of hydrogen in a hydrocarbon with one or more halogens

Nomenclature follows rules of previous sections
ALCOHOLS
1,2-ethanediol or antifreeze

An hydroxyl (-OH) is attached to the end of the hydrocarbon or R

For naming, drop –e parent hydrocarbon with –d

Number placement of hydroxyl group with smallest possible

Alcohols can be primary, secondary, or tertiary
The lower molecular mass alcohols are soluble in water through hydrogen bonding with the
water. Alcohols with four or more carbon atoms however, have such a large nonpolar part of the
molecule that they are not soluble in water, a polar solvent.
ETHERS

Organic oxides with –O- within the body of the molecule

Nomenclature follows basic hydrocarbon rules for both sides of R-O-R, followed by the
second name, ether.
ORGANIC CHEMISTRY Chapter 25
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Mrs. Brunet
dimethyl ether

ALDEHYDES

Contain a carbonyl group bonded to at least one hydrogen atom

Nomenclature drops final –e and adds –al and a number indicating the position of the
carbonyl group, where necessary. (aldehyde carbon is always #1)

Aldehydes have strong odors; two of the best are vanillin (left) and cinnamadlehyde
KETONES

Carbonyl group BUT bonded to two carbon atoms, in the middle

Nomenclature drops the final –e then adds –one

Number the placement of the carbonyl group

Ketones are used as solvents, you use this one on the white boards all the time!


ORGANIC CHEMISTRY Chapter 25
Vacation packet #2
Mrs. Brunet
CARBOXYLIC ACIDS

Carboxyl is from “carbonyl” and “hydroxyl”

Naming: drop –e then add –ioc acid

Weak acids, such as acetic acid, the active ingredient in vinegar

Formic acid (or methanoic acid) is the agent that causes pain from an ant bite
ESTERS


Often have sweet, fruity odors

Esters are formed from an alcohol and an organic acid
Naming: the names of the alcohol is first, dropping the –ol and adding –yl, next the
name of the acid drops –oic and adds –ate

Some esters are used as substitutes for natural products and enhancers in food.
Remember the first lab? You were to identify the ester; some of you smelled octyl
acetate, orange aroma; or ethyl butyrate, pineapple aroma. Other fun ones: methyl
butyrate, apple; isopentyl acetate, banana; pentyl propionate, apricot; isobutyl
formate, raspberry, benzyl acetate, jasmine

Are you a fan of grapples? You can make your own with regular apples and grape ester
found in grape koolaid. http://www.ehow.com/how_5907945_make-grapple-apple.html
ORGANIC CHEMISTRY Chapter 25
Vacation packet #2
Mrs. Brunet

Wintergreen lifesavers have wintergreen oil and can produce a visible spark when
cracked. Live a little…try it! http://www.ehow.com/how_2097426_make-light-sparklifesaver.html
AMINES

Amines are related to ammonia, NH3…you remember
ammonia? A friend of the gravimetric plant food lab

Starting with NH3 replacing one H with a carbon chain
(primary); two H’s (secondary); or three H’s (tertiary).
This makes an amine.

Amines are organic versions of bases

Amines are responsible for unpleasant odors like decaying
tissue, old fish

Aromatic amines (carcinogens) are used to make dyes. Be
careful!

Complex molecules use amino- for the -NH2 functional group
HW 3 p. 111-2 #40,46,52
TYPES OF ORGANIC REACTIONS:
1] Substitution: replacing of one functional group by another
ORGANIC CHEMISTRY Chapter 25
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Mrs. Brunet
2] Addition: it is common for alkenes to break one bond and gain two substituents.
3] Elimination: one product is removed, leaving an unsaturated hydrocarbon, also is called
dehydration
4] Esterification: an alcohol reacts with an organic acid to make an ester
5] Saponification: esters are split into alcohols and salts of carboxylic acids; triglycerides can
be treated with aqueous sodium hydroxide to form glycerol and soaps.
HW 4 p. 1111 #32
ORGANIC CHEMISTRY Chapter 25
Vacation packet #2
Mrs. Brunet
ISOMERS
Two organic compounds may have formulas with exactly the same
atoms but different properties. These compounds are called isomers,
there are three types: structural isomers, cis- and trans- isomers,
stereoisomers.
Structural Isomers: Butane and allother alkanes exhibit structural isomerism. For
example, butane can exist as a straight chain or n-butane (normal butane). The
branched isomer of butane is called isobutene:
Isomers can be difficult to figure and draw, just remember to count the longest continuous
chain. This can often show that some may appear as isomers but really are the same
arrangement. With alkenes and alkynes, try moving the multiple bond around to different
locations because multiple bonds are rigid.
Isomers are discussed all throughout the organic chemistry tutorial by science geek.com
http://www.sciencegeek.net/APchemistry/organic/ochem.shtml
Cis- and Trans- Isomers: These isomers refer to molecules that contain atoms or groups of
atoms in different positions around a rigid ring (rigid = contains multiple bonds) or bond.
Cis- means “on the same side”; Trans- means “on
opposite sides” and refers to groups attached to
double-bonded carbon atoms. The double bond is
the key to the distinctly different molecules which
have different chemical and physical properties as a
result of their structures.
Stereoisomers or Optical Isomerism: These isomers are
the hardest to recognize and take considerable brain power
and spatial thinking to work with; they have the same
formulas, and every atom is bonded to the same atom.
These are not structural isomers, but they are not exactly
ORGANIC CHEMISTRY Chapter 25
Vacation packet #2
Mrs. Brunet
the same. I have to actually make models to get this and fortunately
we are born with two perfect stereoisomers. Left hand meet right
hand. (or feet) They are the same in every way, yet they are not
identical. They are mirror images of each other and that, girls and
boys, is a stereoisomer!
Stereoisomers, unlike cis- and trans- isomers, have identical physical properties such as
melting and boiling points. The chemical reactivity of two stereoisomers is, for the most
part, identical also. However, stereoisomers often have different chemical reactivites in
biological systems (like us) where the overall shape of the molecule is important. Most amino
acids have two stereoisomers. In all known living matter the stereoisomers are those that
rotate light to the left. Yet synthetic production of pharmaceuticals produces 50:50 right
and left isomers, even when only one is effective as a drug. Production of only one of the
isomers is possible but very expensive….sound familiar when considering prescription
medication?
HW 5: AP Problems 
2002 B
Consider the hydrocarbon pentane, C5H12 (molar mass 72.15 g).
(a) Write the balanced equation for the combustion of pentane to yield carbon dioxide and water.
(b) What volume of dry carbon dioxide, measured at 25˚C and 785 mm Hg, will result from the complete
combustion of 2.50 g of pentane?
(c) The complete combustion of 5.00 g of pentane releases 243 kJ of heat. On the basis of this information,
calculate the value of ∆H for the complete combustion of one mole of pentane.
(d) Under identical conditions, a sample of an unknown gas effuses into a vacuum at twice the rate that a
sample of pentane gas effuses. Calculate the molar mass of the unknown gas.
(e) The structural formula of one isomer of pentane is shown below. Draw the structural formulas for the other
two isomers of pentane. Be sure to include all atoms of hydrogen and carbon in your structures.
ORGANIC CHEMISTRY Chapter 25
Vacation packet #2
Mrs. Brunet
2003 D
Compound
Name
Compound
Formula
∆H˚vap
(kJ mol-1)
Propane
CH3CH2CH3
19.0
Propanone
CH3COCH3
32.0
1-propanol
CH3CH2CH2OH
47.3
Using the information in the table above, answer the following questions about organic compounds.
(a) For propanone, draw the complete structural formula (showing all atoms and bonds);
(b) For each pair of compounds below, explain why they do not have the same value for their standard heat of
vaporization, ∆H˚vap. (You must include specific information about both compounds in each pair.)
(i) Propane and propanone
(ii) Propanone and 1-propanol
(c) Draw the complete structural formula for an isomer of the molecule you drew in, part (a) (i).
Testing Review
Naming alkanes: http://www.sciencegeek.net/APchemistry/APtaters/chap22alkanes.htm
Naming Chemical Compounds PowerPoint is good review up until slide 27 where the organic
chemistry starts! I found this on the internet and lost the citing information…oops.