| Swedish
Chemicals Berzelius as a poor family. Was able to study
medicine
at Uppsala. Following did volunteer assistant in Stockholm in
the
faculty of medicine. A. Shortly after the invention of
A. Volta's battery. In 1802 began his chemical
experiments
on the effects of electrical current (W. Nicholson), having by 1803 in
its collaboration with W. Hisinger that all salts are decomposed
electrical. From here developed its dualistic conception (see
below) according to which all inorganic or organic compounds are made
up of positive and negative components. In 1803, again with
the
help of Hisinger, discovered the cerium, which was later followed the
discovery of selenium and thorium. Berzelius Isolated for the first,
silicon, zirconium and titanium.
Base is on the assumption that the smallest particles of a substance
simply have a well-defined electrical polarity. But in each
electricity pole and electricity negative positive do not have the same
strength. Depending on whether one or other domains, the
substance is electro positive or electronegative. Substances
electro positive buy electricity always positive when you join with a
substance electronegative. B. Chemical elements divided into two broad
classes and sign suppose that the power consumption of each item could
change depending on the compound where entered. Only oxygen
was
invariably negative. In this classification the items were
ordered following the progression of their properties positive, those
around the middle of progression electrochemical properties were not
clearly defined. In this way each was composed by the
elements or
groups of elements of electric opposite sign. This
representation
was adopted universally. It remained unchanged in
inorganic
chemistry, even if the progress made in organic chemistry exceeded
(where anyway B. anticipated the idea of radical).
= J. Convinced supporter of the theory of atomic J. Dalton,
Berzelius Wanted to check and compare the various positions
on
the presence of fixed proportions between components of a compound and
no (GEL Proust = e = C.-L. Berthollet) by a huge number of chemical
analyzes conducted on more than 2000 compounds (1807 -- 17) and in
which demonstrated extraordinary analytical ability.
Berzelius,
who in 1815 was appointed professor of chemistry at the Institute of
Medical and surgical Stockholm (retired in 1832), knew how to find an
agreement between the theory atomistic that of fixed proportions and
concepts on the role of the combustion (AL = Lavoisier), building a
table of atomic weights, using oxygen as a base (which attributed the
weight 100). In 1818 he published the table of atomic weights of 45 of
49 chemical elements then known table perfected and expanded in
1828. Berzelius During these searches, developed its system
of
chemical nomenclature. Berzelius Chose as a symbol of the first letter
or Latin name of each element, to avoid confusion and
misunderstandings in the case of ambiguity, the first letter was
followed by a letter. Also obtained the formula of the
substance
composed.
Which the symbols were accompanied by representatives corresponding
numerical units atomic weight of each constituent element the
compound. The principle of this notation has never been
abandoned.
He invented the term to describe catalysis of the phenomenon associated
with the acceleration of the rate of chemical processes (catalytic
action is Acids hydrolysis discovery of starch from GR = Kirchhoff, as
well as that of platinum sponge electrolyze) . The bonds
between
atoms or groups of atoms in molecules were coulombian
origin. She
chose hydrogen as a reference in determining the equivalent weights and
introduced the concept of isomeric (name that dates back to B.) and
allotropic. Studied proteins (again will propose the name, derived from
the greek prèteioj, "Primary "to indicate the key role for
life). Improvement significantly from what was great analyst,
instrumentation, chemical laboratory (inter alia: paper for filtering,
rubber tubes, pipettes of technique, balance). In recent years the
controversy with the chemical younger He make
bitter
deeply.
The entire career of Berzelius Took place in Stockholm and in his
laboratory worked almost all chemical Germans who bought reputation in
the nineteenth century. The prestige of its work, the annual
reviews in which presented and commented on the critical work of his
staff made him a true legislator chemistry. His masterpiece
is
the wording of the dualistic theory and the chemistry of symbolism that
later would have a considerable importance not only for the chemical
language, but also in the representation and discussion of any
reaction. The great Swedish scientist exercised an unopposed
on
the development of the chemical for about 30 years. |
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