History of chemistry
Robert Boyle (1627–1691) pioneered
the scientific method in chemical investigations. He assumed nothing
in his experiments and compiled every piece of relevant data. Boyle
would note the place in which the experiment was carried out, the
wind characteristics, the position of the Sun and Moon, and the
barometer reading, all just in case they proved to be relevant. This
approach eventually led to the founding of modern chemistry in the
18th and 19th centuries, based on revolutionary discoveries of
Lavoisier and John Dalton.
Beginning around 1720, a rigid
distinction began to be drawn for the first time between "alchemy"
and "chemistry". By the 1740s, "alchemy" was now
restricted to the realm of gold making, leading to the popular belief
that alchemists were charlatans, and the tradition itself nothing
more than a fraud.
Practical attempts to improve the
refining of ores and their extraction to smelt metals was an
important source of information for early chemists in the 16th
century, among them Georg Agricola (1494–1555), who published his
great work De re metallica in 1556. His work describes the highly
developed and complex processes of mining metal ores, metal
extraction and metallurgy of the time. His approach removed the
mysticism associated with the subject, creating the practical base
upon which others could build. The work describes the many kinds of
furnace used to smelt ore, and stimulated interest in minerals and
their composition. It is no coincidence that he gives numerous
references to the earlier author, Pliny the Elder and his Naturalis
Historia. Agricola has been described as the "father of
metallurgy"
In 1605, Sir Francis Bacon published
The Proficience and Advancement of Learning, which contains a
description of what would later be known as the scientific
method.[38] In 1605, Michal Sedziwój publishes the alchemical
treatise A New Light of Alchemy which proposed the existence of the
"food of life" within air, much later recognized as oxygen.
In 1615 Jean Beguin published the Tyrocinium Chymicum, an early
chemistry textbook, and in it draws the first-ever chemical
equation.[39] In 1637 René Descartes publishes Discours de la
méthode, which contains an outline of the scientific method.
Anglo-Irish chemist Robert Boyle
(1627–1691) is considered to have refined the modern scientific
method for alchemy and to have separated chemistry further from
alchemy. Although his research clearly has its roots in the
alchemical tradition, Boyle is largely regarded today as the first
modern chemist, and therefore one of the founders of modern
chemistry, and one of the pioneers of modern experimental scientific
method. Although Boyle was not the original discoverer, he is best
known for Boyle's law, which he presented in 1662. The law describes
the inversely proportional relationship between the absolute pressure
and volume of a gas, if the temperature is kept constant within a
closed system. Boyle is also credited for his landmark publication
The Sceptical Chymist in 1661, which is seen as a cornerstone book in
the field of chemistry.
Development
and dismantling of phlogiston:
In 1702, German chemist Georg Stahl
coined the name "phlogiston" for the substance believed to
be released in the process of burning. Around 1735, Swedish chemist
Georg Brandt analyzed a dark blue pigment found in copper ore. Brandt
demonstrated that the pigment contained a new element, later named
cobalt. In 1751, a Swedish chemist and pupil of Stahl's named Axel
Fredrik Cronstedt, identified an impurity in copper ore as a separate
metallic element, which he named nickel. Cronstedt is one of the
founders of modern mineralogy. Cronstedt also discovered the mineral
scheelitein 1751, which he named tungsten, meaning "heavy stone"
in Swedish.
In 1754, Scottish chemist Joseph Black
isolated carbon dioxide, which he called "fixed air".
In 1757, Louis Claude Cadet de
Gassicourt, while investigating arsenic compounds, creates Cadet's
fuming liquid, later discovered to be cacodyl oxide, considered to be
the first synthetic organometallic compound.
In 1758, Joseph Black formulated the
concept of latent heat to explain the thermochemistry of phase
changes.
In 1766, English chemist Henry
Cavendish isolated hydrogen, which he called "inflammable air".
Cavendish discovered hydrogen as a colorless, odourless gas that
burns and can form an explosive mixture with air, and published a
paper on the production of water by burning inflammable air (that is,
hydrogen) in dephlogisticated air (now known to be oxygen), the
latter a constituent of atmospheric air (phlogiston theory).
In 1773, Swedish chemist Carl Wilhelm
Scheele discovered oxygen, which he called "fire air", but
did not immediately publish his achievement.
In 1774, English chemist Joseph
Priestley independently isolated oxygen in its gaseous state, calling
it "dephlogisticated air", and published his work before
Scheele. During his lifetime, Priestley's considerable scientific
reputation rested on his invention of soda water, his writings on
electricity, and his discovery of several "airs" (gases),
the most famous being what Priestley dubbed "dephlogisticated
air" (oxygen). However, Priestley's determination to defend
phlogiston theory and to reject what would become the chemical
revolution eventually left him isolated within the scientific
community.
In 1781, Carl Wilhelm Scheele
discovered that a new acid, tungstic acid, could be made from
Cronstedt's scheelite (at the time named tungsten). Scheele and
Torbern Bergman suggested that it might be possible to obtain a new
metal by reducing this acid.
In 1783, José and Fausto Elhuyar found
an acid made from wolframite that was identical to tungstic acid.
Later that year, in Spain, the brothers succeeded in isolating the
metal now known as tungsten by reduction of this acid with charcoal,
and they are credited with the discovery of the element.
Antoine-Laurent
de Lavoisier:
Antoine-Laurent de Lavoisier
demonstrated with careful measurements that transmutation of water to
earth was not possible, but that the sediment observed from boiling
water came from the container. He burnt phosphorus and sulfur in air,
and proved that the products weighed more than the original.
Nevertheless, the weight gained was lost from the air. Thus, in 1789,
he established the Law of Conservation of Mass, which is also called
"Lavoisier's Law."
Repeating the experiments of Priestley,
he demonstrated that air is composed of two parts, one of which
combines with metals to form calxes. In Considérations Générales
sur la Nature des Acides (1778), he demonstrated that the "air"
responsible for combustion was also the source of acidity. The next
year, he named this portion oxygen (Greek for acid-former), and the
other azote (Greek for no life). Lavoisier thus has a claim to the
discovery of oxygen along with Priestley and Scheele. He also
discovered that the "inflammable air" discovered by
Cavendish - which he termed hydrogen (Greek for water-former) -
combined with oxygen to produce a dew, as Priestley had reported,
which appeared to be water. In Reflexions sur le Phlogistique (1783),
Lavoisier showed the phlogiston theory of combustion to be
inconsistent. Mikhail Lomonosov independently established a tradition
of chemistry in Russia in the 18th century. Lomonosov also rejected
the phlogiston theory, and anticipated the kinetic theory of gases.
Lomonosov regarded heat as a form of motion, and stated the idea of
conservation of matter.
Lavoisier worked with Claude Louis
Berthollet and others to devise a system of chemical nomenclature
which serves as the basis of the modern system of naming chemical
compounds. In his Methods of Chemical Nomenclature (1787), Lavoisier
invented the system of naming and classification still largely in use
today, including names such as sulfuric acid, sulfates, and sulfites.
In 1785, Berthollet was the first to introduce the use of chlorine
gas as a commercial bleach. In the same year he first determined the
elemental composition of the gas ammonia. Berthollet first produced a
modern bleaching liquid in 1789 by passing chlorine gas through a
solution of sodium carbonate - the result was a weak solution of
sodium hypochlorite. Another strong chlorine oxidant and bleach which
he investigated and was the first to produce, potassium chlorate
(KClO3), is known as Berthollet's Salt. Berthollet is also known for
his scientific contributions to theory of chemical equilibria via the
mechanism of reverse chemical reactions.
Lavoisier's Traité Élémentaire de
Chimie (Elementary Treatise of Chemistry, 1789) was the first modern
chemical textbook, and presented a unified view of new theories of
chemistry, contained a clear statement of the Law of Conservation
of Mass, and denied the existence of phlogiston. In
addition, it contained a list of elements, or substances that could
not be broken down further, which included oxygen, nitrogen,
hydrogen, phosphorus, mercury, zinc, and sulfur. His list, however,
also included light, and caloric, which he believed to be material
substances. In the work, Lavoisier underscored the observational
basis of his chemistry, stating "I have tried...to arrive at the
truth by linking up facts; to suppress as much as possible the use of
reasoning, which is often an unreliable instrument which deceives us,
in order to follow as much as possible the torch of observation and
of experiment." Nevertheless, he believed that the real
existence of atoms was philosophically impossible. Lavoisier
demonstrated that organisms disassemble and reconstitute atmospheric
air in the same manner as a burning body.
With Pierre-Simon Laplace, Lavoisier
used a calorimeter to estimate the heat evolved per unit of carbon
dioxide produced. They found the same ratio for a flame and animals,
indicating that animals produced energy by a type of combustion.
Lavoisier believed in the radical theory, believing that radicals,
which function as a single group in a chemical reaction, would
combine with oxygen in reactions. He believed all acids contained
oxygen. He also discovered that diamond is a crystalline form of
carbon.
While many of Lavoisier's partners were
influential for the advancement of chemistry as a scientific
discipline, his wife Marie-Anne Lavoisier was arguably the most
influential of them all. Upon their marriage, Mme. Lavoisier began to
study chemistry, English, and drawing in order to help her husband in
his work either by translating papers into English, a language which
Lavoisier did not know, or by keeping records and drawing the various
apparatuses that Lavoisier used in his labs. Through her ability to
read and translate articles from Britain for her husband, Lavoisier
had access knowledge from many of the chemical advances happening
outside of his lab. Furthermore, Mme. Lavoisier kept records of
Lavoisier's work and ensured that his works were published. The first
sign of Marie-Anne's true potential as a chemist in Lavoisier's lab
came when she was translating a book by the scientist Richard Kirwan.
While translating, she stumbled upon and corrected multiple errors.
When she presented her translation, along with her notes to
Lavoisier. Her edits and contributions led to Lavoisier's refutation
of the theory of phlogiston.
Lavoisier made many fundamental
contributions to the science of chemistry. Following Lavoisier's
work, chemistry acquired a strict quantitative nature, allowing
reliable predictions to be made. The revolution in chemistry which he
brought about was a result of a conscious effort to fit all
experiments into the framework of a single theory. He established the
consistent use of chemical balance, used oxygen to overthrow the
phlogiston theory, and developed a new system of chemical
nomenclature. Lavoisier was beheaded during the French Revolution.
No comments:
Post a Comment