Download Organic Chemistry: Organic Halides and Alcohols

Organic Chemistry:
Organic Halides and Alcohols
Today’s Objectives:
1) Name and draw structural, condensed structural and line diagrams and
formulas for organic halides and alcohols
2) Identify types of compounds from their functional groups, given the structural
formula and name of the functional groups
Section 10.2 and 10.3 (pg. 417-435)
Today’s Agenda: Review


You will have another Hydrocarbon Quiz next
class covering all aliphatic and aromatic
compounds
Today’s agenda:

Pg. 380 #6 (c-e), 7 (c-e)

Pg. 385 #6-8
**7d) 4-methyl (not 3-methyl)

Make the change in your book if not done
already
Hydrocarbon Quiz #2
Aliphatic and Aromatic Compounds
Organic Halides

Organic compounds where one or more hydrogen
has been replaced with halogens (F, Cl, Br, I)
 Common

example: CFC (chlorofluorocarbons)
Nomenclature is similar to naming branch chains of
hydrocarbons, but the branch name used is based
on the halogen used
 chloro-,
fluoro-, bromo-, iodo-
Organic Halides

What do you need to know about organic halides?
 May
by polar or nonpolar molecules or may have a
relatively nonpolar (hydrocarbon) end and a polar
(halide) end (**Remember Electronegativity differences)
 Have higher boiling points than similar hydrocarbons
 Have very low solubility in water but higher solubility
than similar hydrocarbons
 Are typically good solvents for organic materials such
as fats, oils, waxes, gums, resins or rubber
 Usually toxic or ecologically damaging (DDTs and PCBs)
Practice Naming Organic Halides

Draw 1,2-dichloroethane

Draw 2,2,5-tribromo-5-methylhexane
Practice Naming Organic Halides

Name the following:
CH2Cl2
dichloromethane
1,2-dibromoethene
Bonus: Try 1,2-dibromo-1,2-dichloroethene
chlorobenzene
Did You Know?


There is always a
new concept to
learn that extends
what you have
already learned.
In addition to the
structural isomers
that you know
about, there are cis
and trans isomers
Stop and Practice

Homework Book pg. 5 and 6
Alcohols


An alcohol is an organic compound that contains the –OH
functional group (hydroxyl)
 General formula is R-OH (R = rest of molecule)
Alcohols are classified as primary, secondary or tertiary
depending on the number of carbons bonded to the carbon
that contains the hydroxyl group
Common Alcohols



Methanol (also called wood alcohol) is extremely toxic, causing
death and blindness
Ethanol (also known as grain alcohol) is the alcohol found in
alcoholic beverages and is used in the production of vinegar
Gas line antifreeze,
windshield de-icer,
windshield washer
fluid – all contain
methanol
Naming Alcohols
1.
2.
3.
Locate the longest chain that contains an –OH group attached to
one of the carbon atoms. Name the parent alkane
Replace the –e at the end of the name of the parent alkane with
–ol (i.e. butane becomes butanol)
Add a position number before the suffix –ol to indicate the
location of the –OH group

REMEMBER to number the main chain of the hydrocarbon so that
the hydroxyl group has the lowest possible position number
propan-1-ol
Naming Alcohols
If there is more than one –OH group (called polyalcohols), leave
the –e in the name of the parent alkane and put the appropriate
prefix before the suffix –ol (i.e. diol, triol, tetraol)
4.
Name and number any branches on the main chain. Add the
names of these branches to the prefix.
4.

Draw 2,3-dimethylbutan-2-ol
Practice Naming Alcohols

Draw line structural formulas for:
These are the
only two cyclic or
aromatic alcohols
you will need to
know as they get
very complicated
1.
cyclohexanol
2.
phenol
1.
The three isomers of C5H11OH that are pentanols
Alcohols

What do you need to know about alcohols?
Question: Why is the propane used in a barbecue a gas at
room temperature, but propan-2-ol (also known as rubbing
alcohol) a liquid at room temperature?
Answer: Propane is a non-polar hydrocarbon with weak
intermolecular forces, thus it has a low boiling point and is a
gas at room temperature.
Propan-2-ol is an alcohol, with a polar hydroxyl group and
strong intermolecular forces, thus it has a higher boiling point
than propane and is a liquid at room temperature
Alcohols

What do you need to know about alcohols?
Question: Glycerol (propane-1,2,3-triol) is more viscous than
water, and can lower the freezing point of water. When
added to biological samples, it helps to keep the tissues from
freezing, thereby reducing damage. From your knowledge of
the molecular structure of glycerol, suggest reasons to account
for these properties of glycerol.
Answer: Each molecule of glycerol contains three hydroxyl
groups which can hydrogen-bond with water, interfering with
the attractions between water molecules and thus interfering
with the freezing of water. When water in tissues does not
freeze, there is less damage to the tissues.
Application Question


Predict the order of increasing boiling points for the
following compounds, and give reasons for your answer.
butan-1-ol
pentane
1-chlorobutane
Answer: (Lowest b.p.): pentane, 1-chlorobutane, butan-1-ol
Why? All molecules have a similar number of electrons.
Pentane has the lowest boiling point, because it is non-polar so
will only have London forces between the molecules. 1chlorobutane is polar so will have dipole-dipole forces as well
as London forces. Butan-1-ol has the highest boiling point
because its molecules will have all three intermolecular forces,
most importantly, hydrogen bonding
Today’s homework



Pg. 419 #3
Pg. 430 #5,6,7a,9a
 Due tomorrow
What is coming up tomorrow and the next
day?
 Addition,
Substitution, Elimination
 Carboxylic Acids and Esters