Saponification
One of the organic chemical reactions known to ancient man was the
preparation of soaps through a reaction called saponification. Natural
soaps are sodium or potassium salts of fatty acids, originally made by
boiling lard or other animal fat together with lye potash (potassium
hydroxide). Hydrolysis of the fats and oils occurs, yielding glycerol
and crude soap.
In the industrial manufacture of soap, tallow (fat from animals such
as cattle and sheep) or vegetable fat is heated with sodium hydroxide.
Once the saponification reaction is complete, sodium chloride is added
to precipitate the soap. The water layer is drawn off the top of the
mixture and the glycerol is recovered using vacuum distillation.
The crude soap obtained from the saponification reaction contains
sodium chloride, sodium hydroxide, and glycerol. These impurities are
removed by boiling the crude soap curds in water and re-precipitating
the soap with salt. After the purification process is repeated several
times, the soap may be used as an inexpensive industrial cleanser.
Sand or pumice may be added to produce a scouring soap. Other
treatments may result in laundry, cosmetic, liquid, and other soaps.
Dynamite
Nitroglycerin is a heavy, colorless, oily, explosive liquid obtained by
nitrating glycerol.
Nitroglycerin was the first adopted as a commercially useful explosive
by Alfred Nobel. He experimented with safer ways to handle the
dangerous substance; his younger brother Emil and several workers
were killed in 1864 in a nitroglycerin explosion at the family's
armaments factory in Heleneborg, in Sweden.
Alfred Nobel developed the use of nitroglycerin as a blasting explosive
by mixing the nitroglycerine with inert absorbents
(known as
diatomite or kieselgur, a naturally occurring, soft, siliceous
sedimentary rock that is easily crumbled into a fine white to off-white
powder). He named this explosive dynamite and patented it in 1867.
Nitroglycerin is a high explosive that is so unstable, at the slightest jolt,
friction or impact can cause it to detonate. The molecule contains
oxygen, nitrogen, and carbon so when it explodes a lot of energy is
released as the atoms rearrange to form new molecules with strong,
stable bonds like N2 and CO. However, it is the speed of the
decompostition reaction which makes it such a violent explosive. A
supersonic wave passing through the material is what causes the high
explosive material to decompose almost instantaneously. This
instantaneous destruction of all molecules is called a detonation, and
what causes the destructive blast is a result from the rapid expansion
of hot gases. Nitroglycerin has an advantage over some other high
explosives, that no visible smoke is produced, therefore being able to
be a "smokeless powder".[