Sodium Hydroxide

  Sodium hydroxide (SO-dee-um hye-DROK-side) is a white
deliquescent solid commercially available as sticks, pellets,
lumps, chips, or flakes. A deliquescent material is one that
absorbs moisture from the air. Sodium hydroxide also reacts
readily with carbon dioxide in the air to form sodium carbonate.
Sodium hydroxide is the most important commercial caustic. A
caustic material is a strongly basic or alkaline material that
irritates or corrodes living tissue. The compound ranked number
11 among chemicals produced in the United States in 2004.

  Sodium hydroxide is produced commercially simultaneously
with chlorine gas by the electrolysis of a sodium
chloride solution. In this process, an electric current breaks
down sodium chloride into its component elements, sodium
and chlorine. The chlorine escapes as a gas, while the sodium
metal form reacts with water to form sodium hydroxide

2NaCl ! 2Na + Cl2
2Na + 2H2O ! 2NaOH + H2

  Sodium hydroxide can also be produced easily by means
of other chemical reactions. For example, the reaction
between slaked lime (calcium hydroxide; Ca(OH)2) and soda
ash (sodium carbonate; Na2CO3) produces sodium hydroxide:
Ca(OH)2 + Na2CO3 ! 2NaOH + CaCO3
None of these alternative methods can compete economically,
however, with the preparation by electrolysis.

Sodium hydroxide has a great variety of household and
industrial uses. It is the active ingredient in drain cleaners
such as Drano because it breaks up and dissolves the greasy
mass that is responsible for drain blockages. It is also an
ingredient in many other household products, including oven
cleaners, metal polishes, and hair straighteners. Sodium
hydroxide is also used in the preparation of homemade and
processed foods. It is used in the preparation of soft drinks,
chocolate, ice creams, caramel coloring, and cocoa. Hominy, a
starchy food similar to grits, is made by soaking corn kernels
in a solution of sodium hydroxide in water. Bakers glaze
pretzels and German lye rolls with a weak lye solution before
baking them. The lye gives baked goods a crisp crust. Some
people use lye to cure olives.
  The largest single use for sodium hydroxide is in the
production of organic compounds from which polymers are
made, such as propylene oxide and the ethylene amines, and
of the polymers themselves, including the polycarbonates
and epoxy resins. About a third of all the sodium hydroxide
produced in the United States goes to this application.
Another important use of sodium hydroxide is in the pulp
and paper industry, where it is used to digest (break down)
the raw materials from which pulp and paper are made.
About 13 percent of all the sodium hydroxide made in the

  United States goes to this application. Sodium hydroxide is
also an important raw material in the manufacture of soap.
The method by which soap is made has not changed very
much for thousands of years. A fat or oil is added to a boiling
solution of sodium hydroxide in water. The fat or oil hydrolyzes
into its component parts, glycerol and fatty acids. The
sodium hydroxide then reacts with the fatty acids, forming
sodium salts. The sodium salt of a fatty acid is a soap. Sodium
hydroxide is also an important raw material in the manufacture
of inorganic compounds, especially sodium and calcium
hypochlorite, sodium cyanide, and a number of sulfur-containing
compounds. Some other important uses of sodium
hydroxide include:

• In the manufacture of cellophane and rayon;
• As a neutralizing agent during the refining of petroleum;
• In the manufacture of aluminum metal;
• For the refining of vegetable oils;
• As an agent for peeling fruits and vegetables for processing;
• In the extraction of metals from their ores;
• For the processing of textiles;
• In water treatment facilities;
• For etching and electroplating operations; and
• In a wide variety of research laboratory applications.

  Sodium hydroxide is one of the most caustic substances
known and a strong irritant to the skin, eyes, and respiratory
system. Exposure to sodium hydroxide dust, powder, or solid
can cause burning of the skin and eyes, with possible permanent
damage to one’s vision. Ingestion of the compound

causes burning of the mouth, esophagus, and stomach, resulting
in nausea, diarrhea, internal bleeding, scarring, and permanent
damage to the lungs and gastrointestinal system.
More serious results, such as a drop in blood pressure and
collapse, are also possible.

Caffeine

  Caffeine (kaf-EEN) is an organic base that occurs naturally
in a number of plant products, including coffee beans,
tea leaves, and kola nuts. It occurs as a fleecy white crystalline
material, often in the form of long, silky needles. It
usually exists as the monohydrate, C8H10N4O2 H2O, although
it gives up its water of hydration readily when exposed
to air.
  Scientists believe that humans have been drinking beverages
that contain caffeine for thousands of years. The first
recorded reference to a caffeine drink can be found in a
Chinese reference to the consumption of tea by the emperor
Shen Nung in about 2700 BCE. Coffee is apparently a much
more recent drink, with the earliest cultivation of the coffee
tree dated at about 575 CE in Africa.
  Caffeine was first studied scientifically by two French
chemists, Joseph Bienaime´ Caventou (1795–1877) and Pierre
Joseph Pelletier (1788–1842), who were very interested in
the chemical properties of the alkaloids. Between 1817
and 1821, Caventou and Pelletier successfully extracted
caffeine, quinine, strychnine, brucine, chinchonine, and
chlorophyll (not an alkaloid) from a variety of plants. The
first synthesis of caffeine was accomplished in 1895 by the
German chemist Emil Hermann Fischer (1852–1919), who was
awarded the 1902 Nobel Prize in chemistry for his work on
the alkaloids.

  Caffeine belongs to a class of alkaloids called the methylxanthines.
Chocolate, from the cocoa tree Theobroma cacao
contains another member of the class, theobromine. Both
caffeine and theobromine are stimulants, that is, compounds
that act on the nervous system to produce alertness, excitement,
and increased physical and mental activity.
  Caffeine can be extracted from coffee, tea, and kola
plants by one of three methods. These methods are used
primarily to produce the decaffeinated counterparts of the
products: decaffeinated coffee, decaffeinated tea, or decaffeinated
soft drinks. A commercial variation of these procedures
is to treat the waste products of tea or coffee processing, such
as the dust and sweepings collected from factories, for the
extraction of caffeine.
  In the first of the three extraction methods, the natural
product (coffee beans, tea leaves, or kola beans) are treated
with an organic solvent that dissolves the caffeine from the
plant material. The solvent is then evaporated leaving behind
the pure caffeine. A second method follows essentially the
same procedure, except that hot water is used as the solvent
for the caffeine. A more recent procedure involves the use of
supercritical carbon dioxide for the extraction process.
  Supercritical carbon dioxide is a form of the familiar gas
that exists at high temperature and high pressure. It behaves
as both a liquid and a gas. Not only is the supercritical carbon
dioxide procedure an efficient method of extracting caffeine,
but it has virtually none of the harmful environmental and
health problems associated with each of the other two methods
of extraction.
  Caffeine is also made synthetically by heating a combination
of the silver salt of theobromine (C7H8N4O2Ag) with
methyl iodide (CH2I), resulting in the addition of one carbon
and two hydrogens to the theobromine molecule and converting
it to caffeine.
  Caffeine is used in foods and drinks and for medical
purposes. Its primary action is to stimulate the central nervous
system. People drink coffee, tea, or cola drinks to stay
awake and alert because caffeine creates a feeling of added
energy. It does this by increasing heart rate, improving blood
flow to the muscles, opening airways to aid breathing, and
releasing stored energy from the liver to provided added fuel
for the body. In large quantities, caffeine can also cause
nervousness, insomnia, and heart problems. The effects of
caffeine can linger in the body for more than six hours. In
medical applications, caffeine is sometimes used as a heart
stimulant for patients in shock, to treat apnea (loss of breathing)
in newborn babies, to counteract depressed breathing
levels as a result of drug overdoses, and as a diuretic.
  Caffeine stimulates the brain in two ways. First, because
it has a chemical structure similar to that of adenosine, it
attaches to adenosine receptors in the brain. Adenosine is a
substance that normally attaches to those receptors, slowing
brain activity and causing drowsiness. By blocking those
receptors, caffeine increases electrical activity in the brain,
creating a feeling of alertness. Caffeine also works in the
brain like drugs such as heroin and cocaine, although in a
much milder way. Like those drugs, caffeine increases dopamine
levels. Dopamine is a chemical present in the brain that
increases the body’s feeling of pleasure.
Studies have shown that caffeine can become addictive.
People who use the compound eventually need to take more
and more of it to get the same effect. When some people try to
stop using caffeine, they may suffer from headache, fatigue,
and depression, though these symptoms can be controlled
by gradually reducing the amount of caffeine consumed.
Either way, withdrawal symptoms end after about a week.

Glucose

  Glucose (GLOO-kose) is a simple sugar used by plants and
animals to obtain the energy they need to stay alive and to
grow. It is classified chemically as a monosaccharide, a compound
whose molecules consist of five- or six-membered
carbon rings with a sweet flavor. Other common examples
of monosaccharides are fructose and galactose. Glucose
usually occurs as a colorless to white powder or crystalline
substance with a sweet flavor. It consists in two isomeric
forms known as the D configuration and the L configuration.
Dextrose is the common name given to the D conformation of
glucose.
Credit for the discovery of glucose is often given to the
German chemist Andreas Sigismund Marggraf (1709–1782).
In 1747, Marggraf isolated a sweet substance from raisins
that he referred to as einer Art Z cker (a kind of sugar) that
we now recognize as glucose. More than 60 years later, the
German chemist Gottlieb Sigismund Constantine Kirchhof
(1764–1833) showed that glucose could also be obtained from
the hydrolysis of starch and that starch itself was nothing
other than a very large molecule (polysaccharide) composed
of many repeating glucose units. The molecular structure
for glucose was finally determined in the 1880s by German
chemist Emil Fischer (1852–1919), part of the reason for
which he was awarded the 1902 Nobel Prize in chemistry.
  Glucose is synthesized naturally in plants and some single-
celled organisms through the process known as photosynthesis.
In this process, sunlight catalyzes the reaction
between carbon dioxide and water that results in the formation
of a simple carbohydrate (glucose) and oxygen. The overall
reaction can be summarized by a rather simple chemical
equation:
6CO2 + 6H2O ! C6H12O6 + 6O2
However, photosynthesis actually involves a number of
complex reactions that occur in two general phases, the light
reactions and the dark reactions.
Glucose is produced commercially through the steam
hydrolysis of cornstarch or waste products containing cellulose
(a large molecule composed of glucose units) using a
dilute acid catalyst. The product thus obtained is typically
not very pure, but is contaminated with maltose (a disaccharide
consisting of two molecules of glucose joined to each
other) and dextrins (larger molecules consisting of a number
of glucose units joined to each other).

  Glucose is the primary chemical from which plants and
animals derive energy. In cells, glucose is broken down in a
complex series of reactions to produce energy with carbon
dioxide and water as byproducts.
  Glucose also has a number of commercial uses, nearly all
of them related to the food processing business. It is used in
the production of confectionary products; chewing gum; soft
drinks; ice creams; jams, jellies, and fruit preparations; baby
foods; baked products; and beers and ciders. A relatively small
amount is used for non-food purposes, primarily in the production
of other organic chemicals, such as citric acid, the amino
acid lysine, insulin, and a variety of antibiotics.
The most important health problem associated with
glucose is diabetes. Diabetes is a medical condition that
develops when the body either does not produce adequate
amounts of insulin or cannot use that compound properly.
Insulin is a hormone that controls the metabolism of glucose
in the body. If glucose is not metabolized properly, a
person’s body acts as if it is ‘‘starving.’’ Symptoms of diabetes
include excessive hunger, weight loss, and exhaustion.
If left untreated, the condition can result in coma
and death. Diabetics must have an artificial source of insulin
(usually from injections) and watch their diets to keep
these symptoms under control.

Urea

Urea (yoo-REE-uh) is a white crystalline solid or powder
with almost no odor and a salty taste. It is a product of the
decomposition of proteins in the bodies of terrestrial animals.
Urea is produced in the liver and transferred to the
kidneys, from which it is excreted in urine. The compound
was first identified as a component of urine by French chemist
Hilaire Marin Rouelle (1718–1799) in 1773. It was first
synthesized accidentally in 1828 by German chemist Friedrich
Wo¨hler (1800–1882). The synthesis of urea was one of the
most important historical events in the history of chemistry.
It was the first time that a scientist had synthesized an
organic compound. Prior to Wo¨hler’s discovery, scientists
believed that organic compounds could be made only by the
intervention of some supernatural force. Wo¨hler’s discovery
showed that organic compounds were subject to the same set
of natural laws as were inorganic compounds (compounds
for non-living substances). For this reason, Wo¨hler is often
called the Father of Organic Chemistry.

The formation of urea is the evolutionary solution to the
problem of what to do with poisonous nitrogen compounds
that formed when proteins decompose in the body. Proteins
are large, complex compounds that contain relatively large
amounts of nitrogen. When they decompose, that nitrogen is
converted to ammonia (NH3), a substance that is toxic to
animals. If animals are to survive the decomposition of proteins
(as happens whenever foods are metabolized), some
method must be found to avoid the buildup of ammonia in
the body.

  That method involves a series of seven chemical reactions
called the urea cycle by which nitrogen from proteins

is converted into urea. Although high concentrations of urea
do pose a risk to animal bodies, the urea formed in these
reactions is normally excreted fast enough to avoid health
problems for an animal.
Urea is produced commercially by the direct synthesis
of liquid ammonia (NH3) and liquid carbon dioxide (CO2).
The product of this reaction is ammonium carbamate
(NH4CO2NH2):
2NH3 + CO2 ! NH4CO2NH2
Ammonia and carbon dioxide do not react with each
other under normal conditions of temperature and pressure.
If the pressure is raised to 100 to 200 atmospheres (1750 to
3000 pounds per square inch) and the temperature is raised
to about 200C (400C), however, the reaction proceeds efficiently
with the formation of ammonium carbamate. When
the pressure is then reduced to about 5 atmosphere (80
pounds per square inch), the ammonium carbamate decomposes
to form urea and water:
NH4CO2NH2 ! (NH2)2CO + H2O

  Urea is the sixteenth most important chemical in the
United States, based on the amount produced annually. In
2004, the chemical industry produced 5.755 million metric
tons (6.344 million short tons) of urea. Almost 90 percent of
that output was used in the manufacture of fertilizers. An
additional 5 percent went to the production of animal feeds.
In both fertilizers and animal feeds, urea and the compounds
from which it is made provide the nitrogen needed by growing
plants and animals for their good health and survival.
The other major use of urea is in the manufacture of various
types of plastics, especially urea-formaldehyde resins and
melamine.
Urea is also used:
• In the production of personal care products, such as
hair conditioners, body lotions, and dental products;
• In certain pharmaceutical and medical products, such as
creams to treat wounds and damaged skin;
• As a stabilizer in explosives, a compound that places
limits on the rate at which an explosion proceeds;
• In the manufacture of adhesives;
• For the flame-proofing of fabrics;
• For the separation of products produced during the
refining of petroleum;
• In the production of sulfamic acid (HOSO2NH2), an
important raw material in many chemical processes;
• As a coating for paper products; and
• In the production of deicing agents.

Penicillin

  The penicillins (pen-uh-SILL-ins) are a class of antibiotic
compounds derived from the molds Penicillium notatum and
Penicillium chrysogenum. The class contains a number of
compounds with the same basic bicyclic structure to which
are attached different side chains. That basic structure consists of two amino acids, cysteine and valine, joined to each
other to make a bicyclic (‘‘two-ring’’) compound. The different
forms of penicillin are distinguished from each other by
adding a single capital letter to their names. Thus: penicillin
F, penicillin G, penicillin K, penicillin N, penicillin O, penicillin
S, penicillin V, and penicillin X. A number of other
antibiotics, including ampicillin, amoxicillin, and methicillin,
have similar chemical structures.

  Penicillin was discovered accidentally in 1928 by the
Scottish bacteriologist Alexander Fleming (1881–1995). Fleming
noticed that a green mold, which he later identified as
Penicillium notatum, had started to grow on a petri dish that
he had coated with bacteria. As the bacteria grew towards the mold, they began to die. At first, Fleming saw some promise
in this observation. Perhaps the mold could be used to kill
the bacteria that cause human disease. His experiments
showed, however, that the mold’s potency declined after a
short period of time He was also unable to isolate the antibacterial
chemical produced by the mold. He decided that
further research on Penicillium was probably not worthwhile.

As a result, it was not until a decade later that Penicillium’s
promise was realized. In 1935, English pathologist
Howard Florey (1898–1968) and his biochemist colleague
Ernst Chain (1906–1970) came across Fleming’s description
of his experiment and decided to see if they could isolate the
chemical product produced by Penicillium with anti-bacterial
action. They were eventually successful, isolating and purifying
a compound with anti-bacterial action, and, in 1941, began trials
with human subjects to test its safety and efficacy (ability to kill
bacteria). The successful conclusion of those trials not only
provided one of the great breakthroughs in the human battle
against infectious diseases, but also won for Florey, Chain, and
Fleming the 1945 Nobel prize for Physiology or Medicine.

Penicillins are classified as biosynthetic or semisynthetic.
Biosynthetic penicillin is natural penicillin. It is produced by culturing molds in large vats and collecting and
purifying the penicillins they produce naturally. There are
six naturally occurring penicillins. The specific form of penicillin
produced in a culturing vat depends on the nutrients
provided to the molds. Of the six natural penicillins, only
penicillin G (benzylpenicillin) is still used to any extent.
  Semi-synthetic penicillins are produced by making chemical
alterations in the structure of a naturally occurring
penicillin. For example, penicillin V is made by replacing the
-CH2C6H5 group in natural penicillin G with a -CH2OC6H5
group.

  Penicillins are prescription medications used to treat a
variety of bacterial infections, including meningitis, syphilis,
sore throats, and ear aches. They do so by inactivating an
enzyme used in the formation of bacterial cell walls. With the
enzyme inactivated, bacteria can not make cell walls and die
off. Penicillins do not act on viruses in the same way they do
on bacteria, so they are not effective against viral diseases,
such as the flu or the common cold.
A number of side effects are related to the use of penicillin.
These side effects include diarrhea, upset stomach, and
vaginal yeast infections. In those individuals who are allergic to penicillins, side effects are far more serious and include
rash, hives, swelling of tissues, breathing problems, and
anaphylactic shock, a life-threatening condition that requires
immediate medical treatment.
Penicillin may alter the results of some medical tests,
such as those for the presence of sugar in the urine. Penicillin
can also interact with a number of other medications,
including blood thinners, thyroid drugs, blood pressure
drugs, birth control pills, and other antibiotics, in some cases
decreasing their effectiveness.
  Once promoted as wonder drugs, the use of penicillins
has declined slowly because of the spread of antibiotic resistance.
Antibiotic resistance occurs when new strains of bacteria
evolve that are resistant to existing types of penicillin.
One reason that antibiotic resistance has become a problem
is the extensive and often unnecessary use of penicillins.
When they are prescribed for colds and the flu, for example,
they have no effect on the viruses that cause those diseases,
but they encourage the growth of bacteria more able to
survive against penicillins.

Saccharin - Sweet like Sugar

   Saccharin (SAK-uh-rin) is a synthetic compound whose
water solutions are at least 500 times as sweet as table sugar.
It passes through the human digestive system without being
absorbed, so it has an effective caloric value of zero. It is
used as a sugar substitute by diabetics or by anyone wishing
to reduce their caloric intake.
Saccharin was the first artificial sweetener discovered. It
was synthesized accidentally in 1879 when Johns Hopkins
researchers Constantine Fahlberg (1850–1910) and Ira Remsen
(1846–1927) were working on the development of new food
preservatives. The story is told that Fahlberg accidentally
spilled one of the substances being studied on his hand. Some
time later, he noticed the sweet taste of the substance and
began to consider marketing the product as an artificial sweetener.
Fahlberg and Remsen jointly published a paper describing
their work, but Fahlberg, without Remsen’s knowledge,
went on to request a patent for the discovery. He eventually
became very wealthy from proceeds of the discovery, none of

which he shared with Remsen. Remsen was later quoted as
saying that ‘‘Fahlberg is a scoundrel. It nauseates me to hear
my name mentioned in the same breath with him.’’
   which he shared with Remsen. Remsen was later quoted as
saying that ‘‘Fahlberg is a scoundrel. It nauseates me to hear
my name mentioned in the same breath with him.’’
   of an artificial sweetener. By 1902, it had become so popular
in Germany that the German sugar industry lobbied for laws
limiting production of saccharin. Similar actions occurred in
the United States in 1907 and, by 1911, the federal government
restricted use of the compound to overweight invalids.
A shortage of sugar during World War I (1914–1918) led
to the reintroduction of saccharin as a sweetening agent in
foods. Another sugar shortage during World War II (1939–
1945) saw a new boom in saccharin production. This time, the
compound’s popularity continued after the war ended.
Questions about saccharin’s safety have been raised a
number of times in the past. In 1969, for example, the sweetener
cyclamate was found to be carcinogenic, and its use was
banned in the United States. Doubts over saccharin’s safety
resurfaced, partly since it was often mixed with cyclamate in
artificial sweeteners. In 1972, studies with rats suggested
that saccharin too might be carcinogenic, and the U.S. Food
and Drug Administration imposed restrictions on the sweetener’s
use. Later studies attempting to reproduce the 1972
research were largely unsuccessful, and the status of saccharin
as a carcinogen remain unsettled.
In 1977, the Canadian government decided that sufficient
evidence existed to ban the use of saccharin except for use
with diabetics and others with special medical problems. The
U.S. government considered taking similar action, but, after
more than a decade of reviewing the evidence, decided to
allow the use of saccharin among the general public. Nonetheless,
the status of saccharin as a potential health hazard
remains the subject of an active debate in the United States
and other parts of the world.
  
   A number of methods are available for the synthesis of
saccharin. For many years, the most popular process was one
developed by the Maumee Chemical Company of Toledo,
Ohio, in 1950. This method begins with anthranilic acid
(o-aminobenzoic acid; C6H4(NH2)COOH), which is treated successively
with nitrous acid (HNO2), sulfur dioxide (SO2),
chlorine (Cl2), and ammonia (NH3) to obtain saccharin.
Another process discovered in 1968 starts with o-toluene,
which is then treated with sulfur dioxide and ammonia to
obtain saccharin.
   Saccharin is not very soluble, so it is commonly made
into its sodium or calcium salt (sodium saccharin or calcium
saccharin), both of which readily dissolve in water, for use in
drinks and cooking. Saccharin is often blended with other
sweeteners to reduce its metallic aftertaste.

   Saccharin is used almost exclusively as an artificial
sweetener in food and drinks to replace sugar. Its lack of
calories makes it suitable for diet products and for medical
preparations designed for people who must reduce their caloric
intake. It also finds some small application as a food
preservative, as an antiseptic agent, and as a brightening
agent in electroplating procedures.
Raw saccharin can be an irritant to the skin, eyes, and
respiratory system. If ignited, it burns with the release of
irritating fumes. Only individuals who come into contact

with large quantities of saccharin are likely to be concerned
about such safety problems, however.