The Foundations of Chemistry

(Marcin) #1
Groups other than hydrogen can be substituted by other atoms or groups of atoms.
For example, the bromine atom of an alkyl bromide can be replaced with a hydroxyl group
to form an alcohol. The mechanism of this type of reaction is often studied in introduc-
tory organic chemistry courses.

Alcohols react with common inorganic oxyacids to produce inorganic esters.For
instance, nitric acid reacts with alcohols to produce nitrates by substitution of nitrate,
XONO 2 , for hydroxyl, XOH.

CH 3 CH 2 OHHNO 3 88n CH 3 CH 2 XONO 2 H 2 O
ethanol nitric acid ethyl nitrate

The substitution reaction of nitric acid with glycerol produces the explosive nitroglyc-
erine. Alfred Nobel’s (1833–1896) discovery in 1866 that this very sensitive material could
be made into a “safe” explosive by absorbing it into diatomaceous earth or wood meal led
to his development of dynamite.

Cold, concentrated H 2 SO 4 reacts with alcohols to form alkyl hydrogen sulfates.The
reaction with lauryl alcohol is an important industrial reaction.

CH 3 (CH 2 ) 10 CH 2 XOHoHOSO 3 Ho88nCH 3 (CH 2 ) 10 CH 2 XOSO 3 HH 2 O
1-dodecanol(lauryl alcohol) sulfuric lauryl hydrogen sulfate
acid

The neutralization reaction of an alkyl hydrogen sulfate with NaOH then produces the
sodium salt of the alkyl hydrogen sulfate.

CH 3 (CH 2 ) 10 CH 2 XOSO 3 HNaOH88nCH 3 (CH 2 ) 10 CH 2 XOSO 3 NaH 2 O
sodium lauryl sulfate (a detergent)

Sodium salts of the alkyl hydrogen sulfates that contain about 12 carbon atoms are excel-
lent detergents. They are also biodegradable. (Soaps and detergents were discussed in
Section 14-18.)

ADDITION REACTIONS


An addition reactioninvolves an increasein the number of atoms or groups attached
to carbon. The molecule becomes more nearly saturated.

27-17




H 2 SO 4
3HNO 3

glycerol glyceryl trinitrate
(nitroglycerine)

H 2 C

H 2 C

OH

HC OH HC ONO 2 3H 2 O

H 2 C ONO 2

H 2 C ONO 2
OH

CH 3 CH CH 3 OH Br

Br

CH 3 CH CH 3

OH

Simple inorganic esters may be
thought of as compounds that contain
one or more alkyl groups covalently
bonded to the anion of a ternary
inorganic acid. Unless indicated, the
term “ester” refers to organic esters.


1088 CHAPTER 27: Organic Chemistry I: Formulas, Names, and Properties


Interestingly, nitroglycerine (“nitro”) is
taken by some who have heart disease.
It acts as a vasodilator (dilates the
blood vessels) to decrease arterial
tension.


Nobel’s brother had been killed and
his father physically disabled in a
nitroglycerine explosion in 1864.
Nobel willed $9.2 million to establish
a fund for annual prizes in physics,
chemistry, medicine, literature, and
peace. The prizes were first awarded
in 1901.

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