“Their Structures, Physical
Properties and Nomenclature”
Structure and Physical
An organic compound containing a
hydroxyl group attached to an alkyl group.
a non-polar (alkane-like) chain.
a polar hydroxyl group.
Alcohols have the general formula: R-OH, where “R” involves a
saturated C-atom (bound to hydrogen's and/or other carbons).
Classification of alcohols
• Alcohols may be classified as 1o (Primary), 2o (Secondary), or 3o
(Tertiary), by considering the number of carbons bound to the
•Ethanol is a primary alcohol because there is only one alkyl
group attached to the carbon that carries the OH substituent.
•The isopropyl alcohol found in rubbing alcohol is a
•An example of a tertiary alcohol is tert-butyl (or t-butyl)
alcohol or 2-methyl-2-propanol.
R-O-H has a structure similar to that of water
Higher boiling points.
Classification of alcohols
The Lower the molecular weight of alcohols, the higher the
solubility in water.
The water-solubility of alcohols depends on the length of
the alkyl chain in the alcohol.
alcohols having chains longer than four carbons are not
3-4 carbons or less— ARE soluble in water
Alcohols with more than one hydroxyl group (polyhydroxyl alcohols)
have higher boiling points than monohydroxyl alcohols.
We already saw that the boiling points of alkanes increase with
increasing chain length. The same is true for alcohols.
Alcohols having chains SHORTER than four carbons are very
Methanol is Soluble and Miscible in water…
Alcohols having chains LONGER
than Three carbons are not very
Butanol is Soluble but not Miscible
Water (g/100 g)
CH3OH methanol infinitely soluble
CH3CH2OH ethanol infinitely soluble
CH3(CH2)2OH propanol infinitely soluble
CH3(CH2)3OH butanol 9
CH3(CH2)4OH pentanol 2.7
CH3(CH2)5OH hexanol 0.6
CH3(CH2)6OH heptanol 0.18
CH3(CH2)7OH octanol 0.054
CH3(CH2)9OH decanol insoluble in water
Solubilities of ALCOHOL in water
Structural Formula Name
methanol 32 65 infinite
ethane 30 -89 insoluble
ethanol 46 78 infinite
propane 44 -42 insoluble
1-propanol 60 97 infinite
butane 58 0 insoluble
8 g/100 g117741-butanol
pentane 72 36 insoluble
Comparison between the Boiling points and
Solubility of ALKANES and ALCOHOLs
Phenols are compounds in which the hydroxyl group is attached
to a benzene ring.
Phenol is the simplest member of a family of compounds in which
an -OH group is attached directly to a benzene ring.
Structure Of Phenol
Pure phenol is a white crystalline solid, smelling of disinfectant.
The crystals are often rather wet and discolored.
Phenols have the formula Ar-OH
Ar must be an aromatic ring (e.g., Benzene)
Widely used in healthcare as:
Melting and boiling points
high melting and boiling points ...DocumentsMr. BLITHEDocumentsmy
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Hydrogen bonds can form between a lone pair
on an oxygen on one molecule and the hydrogen
on the -OH group of one of its neighbors.
Solubility in water
Phenol is moderately soluble in water - about 8 g
of phenol will dissolve in 100 g of water.
Phenol is somewhat soluble in water because of its
ability to form hydrogen bonds with the water.
Ethers are a class of organic compounds characterized by an
oxygen atom connected to two hydrocarbon groups.
Ethers do not H-bond with themselves, so have boiling points
similar to hydrocarbons
Ethers are only slightly soluble in water and are highly
Structure of ETHERS
An ether is a characterized by an oxygen bonded to two alkyl
or aryl groups, represented here by R and R'.
The substituent's can be, but do not need to be, the same.
Ethers can act as a hydrogen-bond acceptor,
as shown in the figure on the right. But, they
can't act as hydrogen-bond donors.
Less likely to be soluble in water than the alcohol with the same
The absence of an -OH group in an ether also has important
consequences for its chemical properties.
Ethers are essentially inert to chemical reactions. They don't react
with most oxidizing or reducing agents, and they are stable to
most acids and bases, except at high temperatures.
However, extremely FLAMMABLE explode if exposed to air for
longer periods of time, to form EXPLOSIVE PEROXIDES.
Melting and Boiling points
Boiling points and melting points are dictated by intermolecular
Compared with alkane of similar molar mass, an ether will have a
similar boiling point.
Compared to an alcohol of the same molar mass, the ether will
have a much lower boiling point.
Medical use of Ethers
Ethers are often used as anesthetics
Accumulate in the lipid material of nerve
cells interfering with nerve impulse
Today halogenated ethers are used
routinely as general anesthetics
Safer to store and to work with
Name the C-atoms of a single alkyl group as for alkanes.
Add the word “alcohol” following a space after the alkyl
1) CH3--OH methyl alcohol
2) CH3 CH2--OH ethyl alcohol
Try this one:
Alcohols with more than one OH group
Polyhydroxyl alcohols possess more than one OH group.
Alcohols which possess two OH groups are called “diols” and
those with three OH groups are called “triols”
Naming this kind of Compound is simple, just follow this:
Alkane name + the number of the OH
1,2-Ethanediol 1,2-Propanediol 1,2,3-Propanetriol
1. Name the parent compound.
2. Replace the –e with –ol.
3. Number the ring to minimize number of carbon with the –OH
4. Identify, name, and number all substituent/s.
Six Carbon ring= Cyclohexane
methyl on C-3
Note: OH must be at C-1
Compounds with additional substituent's are named as
when there is only one other substituent, Ortho, Meta or Para
Mono-substituted phenols are characterized using the prefix
ortho (o-), meta (m-) or para (p-) depending on the placement of
the substituent from the hydroxyl group.
ortho: (1,2-) meta :(1,3-) para : (1,4-)
o-chlorophenol m-chlorophenol p-chlorophenol
If there are two or more additional substituent's, each must be
numbered, beginning at the OH and going in direction that gives
substituent's lowest numbers (or alphabetical if same in both
The simplest member of phenol is called phenol itself or
hydroxybenzene and the rest are named as its derivatives.
Functional group suffix = -common - phenol, systematic -
Functional group prefix = hydroxy
di , tri and so forth are used to denote the number of
NOTE: Many have common or trivial names that do not at all
suggest the structure…
For common names: name each alkyl group
attached to the oxygen followed by ether.
1. CH3-CH2-O-CH2-CH3 Diethyl Ether
2. CH3-CH2-O-CH3 Ethyl methyl Ether
Methyl phenyl Ether
For complex ethers IUPAC names are used
Step1: Name as an alkane, with larger alkyl group being the
Step 2: Find the smaller alkyl group and the O are named
together as an alkoxy group (replace -yl with -oxy)
e.g., CH3CH2O = ethoxy
Step 3: Number chain starting at end nearest alkoxy group
Step 4: Use a number to give location of alkoxy group
Try this one:
Naming Cyclic Ethers
Cyclic ethers are generally named by their common
A cyclic ether containing two carbons is called
ethylene oxide (generally known as epoxides)
A cyclic ether containing 4 carbons (with 2 double
bonds) is called a furan
A cyclic ether containing 5 carbons (with 2 double
bonds) is called a pyran
A cyclic ether containing 4 carbons and 2 oxygens is
called a dioxane
PHENOLS are next-generation anti-oxidant found
throughout nature in some of the healthiest foods.
PHENOLS are the common health-giving link that ties
together foods, such as Red Wine, Green Tea, Dark Chocolate,
In human health these compounds are thought to be instrumental
in combating oxidative stress, a process associated with some
neurodegenerative diseases and some cardiovascular diseases.
Approximately 600,000 students per year are assaulted
by a drinking student.
Research suggests that women are more vulnerable
than men to many alcohol- induced problems. Some of
these include, Organ Damage, Trauma, Legal and
Alcohol affects men and women differently. Women
become more impaired than men from drinking the same
amount of alcohol. This is because women:
• Are generally smaller in size
• Have less body water
• Have less dehydrogenase.
• Have more estrogen
Alcohol is a central nervous system depressant. In small
amounts it can have a relaxing effect.