Chem 112 Class Guide: FUCNTIONAL GROUPS
Chapter 24, Section 4 Learning Goals:
Upon completion of Chapter 24, Section 4, you should be able to determine the following:
Identify the functional groups in an organic molecule
Name simple molecules with an attached functional group
Chapter reading Guide: Chapter 24, Section 4
Section 4: Organic Functional Groups
Read Chapter 24.4
A functional group is a group (often containing O, S or N) of atoms in an organic molecule
that determine the type of reactions that organic molecules can undergo.
It is important to be able to identify the most major functional groups and to name
compounds containing some of the functional groups.
There is a table of functional groups on page 1022 of your textbook. It looks similar to the
image below:
You are responsible for identifying all groups and naming the following groups:
Alkenes and alkynes (discussed in sections 1, 2 and 3)
Alcohols
Terminal amines (i.e., amines at one end of a molecule)
Terminal amides (i.e., amides at one end of a molecule)
Aldehydes
Ketones
Carboxylic acids
TO NAME TERMINAL AMINES, TERMINAL AMIDES, ALDEHYDES AND CARBOXYCLIC ACIDS:
1.) Name as discussed in Chapter 24, Sections 1-3
2.) Instead of ending in –ane, #-ene or #–yne, endings are:
a) Terminal amines end in –amine
b) Terminal amides end in –amide
c) Aldehydes end in –al
d) Carboxylic acids end in –oic acid
Examples:
Amine:
The longest chain, shown in blue, is 3 carbons long. The parent name is prop.
The functional group is an amine (shown in pink) and is located on carbon 1 (remember that
we start numbering at the end closest to a functional group).
There is a methyl substituent (shown in green) off of carbon 2.
The whole name should be: 2-methylpropyl-1-amine.
Amide:
The longest chain, shown in blue, is 5 carbons long. The parent name is pent.
The functional group is an amide (shown in pink) and is located on carbon 1.
There is a methyl substituent (shown in green) off of carbon 4.
The whole name of this compound should be: 4-methylpent-1-amide.
Aldehyde:
The longest chain, shown in blue, is 8 carbons long. The parent name is oct.
The functional group is an aldehyde (shown in pink) and is located on carbon 1. Note that
for aldehydes, we show the H attached to the carbon.
There is a methyl substituent (shown in green) off of carbon 3.
There is an ethyl substituent (shown in red) off of carbon 5.
The whole name of this compound should be: 5-ethyl-3-methyloct-1-al.
Carboxylic Acid:
The longest chain, shown in blue, is 8 carbons long. The parent name is oct.
The functional group is a carboxylic acid (shown in pink) and is located on carbon 1.
There is a methyl substituent (shown in green) off of carbon 3.
There is an ethyl substituent (shown in red) off of carbon 4.
The whole name of this compound should be: 4-ethyl-3-methyl-oct-1-oic acid
TO NAME ALCOHOLS AND KETONES:
1.) Name as discussed in Chapter 24, Sections 1-3
2.) Instead of ending in –ane, #-ene or #–yne, end in:
a) Alcohols end in #-ol where # is the number of the carbon in the chain that the –OH
group is on
b) Ketones end in #-one where # is the number of the carbon in the chain that the –OH
group is on
Examples:
Alcohol:
The longest chain (shown in blue) is 5 carbons long. The parent name is pent.
The functional group is an alcohol (shown in pink) and is on carbon 2.
There is a methyl substituent (shown in green) on carbon 4.
The whole name of this compound should be: 4-methylpent-2-ol.
Ketone:
The longest chain (shown in blue) is 4 carbons long. The parent name is but.
The functional group is a ketone (shown in pink) and is on carbon 2.
There are no other substituents on this molecule.
The whole name of this compound should be: but-2-one.
Learning Resources
Chapter Learning Goals
Chapter 24, Section 4 Learning Goals
Pre Class Assignment: This assignment must be completed prior to the next class. Check your syllabus
for the exact due date and time.
Complete to the pre class assignment
(http://berks.psu.edu/clt/chem112/FunctionalGroups_HW.docx)
Submit a copy to the dropbox located in ANGEL called “Pre Class Assignment Submission:
Functional Groups”
End of Chapter Problems:
Practice with these problems if you are having difficulty with any of the concepts covered in this
class guide AFTER we have met in class. If you cannot easily complete these problems, seek
help from your instructor, your mentor or the learning center
Chapter 24: 43 and 47. Be able to name 43 a, 43 c, 43 e and 43 f.