Chem 2 Organic Part 2 Day 67: Alcohols and Acids
Substituted Hydrocarbons: These are chains of carbon with a functional group at some
position on the chain. Each group has a general formula that will identify it. Memorize
the general formulas to help in your naming and drawing of the groups.
Substituted Hydrocarbon groups
Alcohols
Acids
Aldehydes
Ketones
Esters
Ethers
Amines
Amides
Nitriles
Fatty Acids
Alcohols
Amino Acids
GF: R-OH
these are organic hydroxides (organic bases)
Three classes of alcohols exist
n or normal alcohols have the OH attached on an end chain carbon.
iso or secondary (sec) alcohols have the OH attached an inner C (iso position). This C is
attached to two other C atoms.
neo or tertiary alcohols have the OH attached to an inner carbon that is attached to three
other carbon atoms.
The alcohols are named by dropping the -e from the alkane name and adding -ol
The alcohol can also be named by using the alkyl group and adding the word alcohol.
CH3OH is methanol or methyl alcohol.
Alcohols are prepared by the action of yeast on sugar or by adding water to an alkene.
Alcohols have a polar end and a non polar end to the molecule-the OH end is polar. They
make good solvents.
Draw n butanol, isobutanol and tertbutyl alcohol. (C4H9OH)
Some chains can contain more that one –OH
Draw 1,2 ethane diol
This is called ethylene glycol and us used as antifreeze in
engines. It is sweet but is a poison especially to cats and dogs.
The formula is C2H4(OH)2
Propylene glycol is 1,2 propane diol. It is a preservative and also used as an antifreeze.
Draw
1, 2, 3 propane triol is called glycerin or glycerol and is used in most hand lotions
because it helps hold moisture on the skin (hygroscopic)
Glycerin reacts with nitric acid to make nitroglycerin-unstable-explosive but is absorbed
into sawdust to make dynamite.
A hydroxide can replace an H on the benzene and become phenol (commonly called
carbolic acid) C6H5OH
Benzyl alcohol attaches a C to the benzene ring in place of an H and then adds and H,
another H and an OH to the three bond sites of the carbon. Draw.
Water and alcohols form an azeotrope in which the liquid solution and the vapor that
forms during boiling will have the same % makeup. A solution that has 90 % water and
10 % alcohol will produce a vapor that has the same makeup.
Another unique property of alcohol and water is that 50 ml of water and 50 ml of ethanol
will not give 100 ml of solution. The dissolving gives less volume than expected.
The test for an alcohol is the iodoform test. An alcohol is treated with NaOh and Iodine
crystals and will form a yellow precipitate.
Long chains of alcohols are called steroids
C8H17 Chain
Ergosterol is also known as Vitamin D-can’t be made by the body, must come from food
or supplements. It needs sunlight for body conversion
C28H44O
OH
DES diethylstibesterol is a steroid used to help cattle gain weight but must be closely
monitored so the chemical is not carried over in the meat after slaughter of the cattle.