1
Additional Structures to Accompany Exp. 16
Introduction to Models
Goals:
 Draw formulas for alkanes from their three-dimensional models.
 Write the names of alkanes from their structural formulas.
 Construct models of isomers of alkanes.
 Write structural formulas for designation of functional groups.
Introduction:
The saturated hydrocarbon represents a group of organic
compounds composed of carbon and hydrogen. Alkanes and cycloalkanes are
called saturated hydrocarbons because their carbon atoms are connected by
only single bonds. In each type of alkane each carbon must have four valence
electrons and must always have four single bonds.
To learn more about the three dimensional structure of organic
compounds, it is helpful to build models using ball and stick model kit. In the kit
are wooden (or plastic) spheres which represent the typical elements in organic
compounds. Each wooden atom has the correct number of holes drilled for
bonds that attach to other atoms.
Table 16A.1 Elements and Bonds Represented in the Organic Model Kit
Color
Element
Number of Bonds
Black
Carbon
4
Yellow or White
Hydrogen
1
Red
Red
2
Green
Halogen (F, Cl, Br, or I)
1
Blue
Nitrogen
3
Silver
Hexavalent (not used)
6
Longer bonds or springs
C, N, O
Multiple (double or triple)
Shorter bonds or sticks
Any
Single bonds
1. First we will build methane, CH4. We will also show the three ways to
draw this structure.
A) 3-dimensional
B) Complete Structural formula
C) Condensed structural formula
2
Table 16A.2 Complete the table by drawing the first 10 Alkanes:
Name
Condensed
Complete
Draw at least one
formula
structural
isomer
AND
Formula
name it
Methane
CH4
Name: _________
Ethane
CH3CH3
Name: _________
Propane
Name: _________
Butane
Name: _________
Pentane
Name: _________
Hexane
Name: _________
Heptane
Name: _________
Octane
Name: _________
Nonane
Name: _________
Decane
Name: _________
3
Table 16A.3 Fill in the table and find the functional groups:
Condensed formula
Full Structural Formula
Organic Family
(functional group)
CH3-OH
CH3-CH2-CH3
CH2=CH2
CH3-O-CH3
O
CH3-C—OH
CH3-NH2
O
CH3-C-CH3
O
CH3-N-CH3
CH3-CH2-CH=CH-CH3
CH3-CH2-NH-CH2-CH3
CH3-CH2-O-CH3
CH3CH2CH2COOH
4
Additional Structures to Accompany Lab 18
Structures of Alkanes
Goals:
 To determine names and shapes of halogenated organic compounds
 To determine the name and shape of cycloalkanes
 To determine the name and shape of branched alkanes
Table 18A.1 Complete the table for the haloalkane
Name
Complete Structural
Condensed structural
formula
formula
Chloromethane
1,2-dibromoethane
2-iodopropane
Table 18A.2 Complete the table by creating four isomers of dichloropropane
Name
Complete structural
formula
Condensed structural
formula
5
Table 18A.3 Complete the table by creating the cycloalkane with the
appropriate number of carbons.
Number of C
Name
Condensed
Geometric
atoms
structure
Formula
3
4
6
8
Table 18A.4 Complete the table
Name
Condensed
Structure
ethyne
2-methyl-2pentene
phenol
Complete
Structural
Formula
Geometric
formula (if
applicable)
6
ADDITIONAL STRUCTURES FOR
ALCOHOLS AND PHENOLS
LAB 19
Goals:
 Determine chemical and physical properties of alcohols and phenols
 Classify an alcohol as primary, secondary, or tertiary
 Name and build models of various alcohols
Introduction: Alcohols are organic compounds that contain the hydroxyl group (-OH).
The simplest alcohol is methanol. Ethanol is found in alcoholic beverages and
preservatives and is used as a solvent. Isopropanol or 2-propanol is used as a
disinfectant and is found in perfumes. The abbreviations for alcohols may be MeOH for
methanol or EtOH for ethanol. What would be the abbreviation for n-propanol?
Table 19A.1 Fill in the table for the simple alcohols listed.
Name
Condensed Structure
Methanol
Complete Structure
Ethanol
Isopropanol or 2-propanol
A benzene ring with a hydroxyl group is known as phenol. Concentrated solutions of
phenol are caustic and cause burns. It is a weak acid that is soluble in water. However,
derivatives of phenol, such as thymol, are used as antiseptics and are sometimes found
in cough drops.
Table 19A.2 Fill in the table for these aromatic alcohols
Name
Condensed Structure
Phenol
Complete Structure
Thymol (2-isopropyl-5methylphenol)
Thiols and Diols: A thiol contains an –SH group. The name is given the alkane chain
name then thiol is after it as one word. Ex. CH3CH2SH is ethanethiol
Diols contain TWO –OH groups. We will not be naming diols, but you should know what
they are and how to recognize this functional group.
7
Classification of Alcohols: In a primary (10) alcohol, the carbon atom attached to the –
OH group is bonded to one other carbon atom. In a secondary (20) alcohol, it is attached
to two carbon atoms and in a tertiary (30) alcohol to three carbon atoms.
Table 19A.3 Fill in the table describing if the alcohol is primary, secondary, or tertiary.
Name
Condensed
Complete
10, 20, or 30
structure
structure
Ethanol
t-butyl alcohol (2methyl-2-propanol
1methylcyclopentanol
3-pentanol
Cyclohexanol
Table 19A.4 Fill in the missing information in the table below.
Name
Condensed
Complete formula
formula
3,4 di-methylhexane
2,2,4trimethylhexane
3-ethyl2,4,5trimethylhexane
1-ethyl-3-methyl-5propylcyclohexane
4-chloro-4,5dimethyl-2-hexene
Functional group
or Organic family
8
ETHERS
Ethers contain an oxygen atom that is attached by a single bond to two carbon
groups that are alkyls or aromatic rings. Ethers have a bent structure like water
and alcohols. Most ethers are named by their common names. The IUPAC
names are used only when the ether is more complex.
Step 1
Step 2
Step 3
For simple ethers, use the common name. Write the name of each
alkyl or aryl (aromatic) group attached to the oxygen atom in
alphabetical order followed by the word ether.
For more complex ethers, use IUPAC naming. Use the alkane
name of the larger alkyl group as the main chain. Name the oxygen
and smaller alkyl group as a substituent called an alkoxy (alkyl +
oxygen) group.
Number the main chain beginning at the end nearest the alkoxy
group and give the location of the alkoxy group on the main chain.
Ex. CH3-O-CH3 = dimethyl ether (common name)
Ex.
-O – CH3 methoxycyclobutane (IUPAC) or cyclobutyl methyl ether (common)
19A.5 Fill in the table for the following ethers
Common name
IUPAC name
Condensed
Structure
Methoxymethane
Diphenyl ether
Ethoxyethane
2-methoxybutane
Ethyl propyl ether
Complete
Structure
9
Additional Structures for Lab 20
Aldehydes and Ketones
Goals:
 Write functional groups of aldehydes and ketones
 Determine chemical and physical properties of aldehydes and ketones
 Name and create models of aldehydes and ketones
Introduction:
Structures of some Aldehydes and Ketones: Aldehydes and ketones contain
the carbonyl group. In an aldehyde, the carbonyl group has a hydrogen attached;
the aldehyde functional group occurs at the end of the carbon chain. In a ketone,
the carbonyl group is located between two of the carbon atoms within the chain.
Write the generic form of aldehydes: ________________________________
Write the generic form of ketones: __________________________________
Properties of Aldehydes and Ketones: Many aldehydes and ketones have
sharp odors. If you have taken biology class, you may have noticed the odor of
FormalinTM, which is a solution of formaldehyde. When you remove fingernail
polish, you may notice the strong odor of acetone, the simplest ketone, which is
used as a solvent. Aromatic aldehydes have a variety of odors. Benzaldehyde,
the simples aromatic aldehyde, has an odor of almonds.
Table 20A.1 Fill in the missing information in the table
Name
Condensed Formula
Formaldehyde
IUPAC name: ________
Acetaldehyde
IUPAC name: ________
Acetone
IUPAC name: _________
Butanone
IUPAC name: _________
Cyclohexanone
Complete structural
formula
10
Benedict’s test is used to distinguish aldehydes from ketones. When in contact
with an aldehyde the oxidiation occurs because the Cu2+ bluish ion contained in
Benedict’s solution becomes a reddish Cu+ (reduced). The copper cation is
reduced whereas the aldehyde is oxidized. Ketones cannot oxidize so the copper
ion remains blue.
Table 20A.2 Fill in the following table
Name
Condensed
Formula
Complete
Structural
Formula
Functional
Group
CH3CH2CCH
3-methylcyclohexene
Trans-2-pentene
m-ethyltoluene
2,2,5trimethylcyclohexanol
CH3CH2CH2SH
Begin working on the structures in your lab practical review. Try to do as many
as you can without looking up the structures.