Lavoisier, Proust
and Berthollet
and the Laws
of Conservation
of Matter and
Definite
Proportions
By Sean Alfonso and
Andrew Kelly
Antoine Lavoisier
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Born 26 of August 1743 and Executed
8 May 1794
He entered Le College Mazarin when
he was 11
During his last 2 years at the college
he grew interested in science
(astronomy, chemistry' botany)
He graduated with a degree in law
but pursued scientific research on the
side
When he was 26 he was elected to
the Academy of Sciences where he
helped develop the metric system
He also was a member of the Ferme
Generale which was in charge of
taxation of French Commoners.
Lavoisier’s Scientific
Contribution
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Lavoisier is considered "the Father of Modern Chemistry"
and created the Law of Conservation of matter and The
law of definite Proportions
His rival was Joseph Priestly and phlogiston theory which
proposed a fire-like element called phlogiston, contained
within combustible bodies.
Phlogiston theory also claimed that weight and thus mass
was affected by temperature.
Lavoisier made a number of experiments, all done in closed
vessels, where total weight remained constant.
In the end he disproved phlogiston theory.
Although he was not the first to test the conservation of
mass but he is credited for its discovery.
Joseph Proust
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Born September 26 1754 in Angers
France, Died July 5 1824 in Angers
France
Was taught chemistry by his
father who was the town
Apothecary
Under Carlos IV's influence Proust
went to Spain. There he taught at
the Chemistry School in Segovia
and at the University of
Salamanca. But was forced to
move back to France when
Napoleon invaded Spain.
Proust’s Scientific Contribution
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He proved that the relative quantities of any given
pure chemical compound’s constituent element
remains invariant, regardless of the compounds
source.
In basic terms: A compound’s elemental composition
always remains the same, no matter the source.
This became known as the law of definite
proportions, this disapproved Berthollet’s theory.
He did this by studying copper sulfate and when he
recreated it, he then compared it to naturally
occurring copper sulfate and observed they both
held the same weight proportions of the elements in
the compound.
Proust showed that cupric (copper II) carbonate
always had 5.3 parts copper to 1 part carbon to 4
parts oxygen
Claude Louis Berthollet
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He was born on December 9th, 1748 in the
town of Talloires, france He died on
November 6th, 1822
He began his studies at Chambery, but
finished his studies at Turin university, where
he graduated in medicine.
Was an active participant in the Academy
of Science
Went with Napoleon to Egypt, and became
a member of the physics and natural history
section of the Institut d’Egypt
Was elected a Fellow of the Royal Society of
London
In 1801 he was elected as a foreign member
of the Royal Swedish Academy of Sciences,
and was elected as a Foreign Honorary
Member of the American Academy of Arts
and Sciences in 1822
Berthollet’s Scientific Contribution
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Devised a system of names which serves as the basis of the
modern system of naming chemical compounds.
Determined the chemical composition of ammonia.
Had an on going feud with Joseph Proust on the law of
definite proportions, we already know what Proust thought,
but Berthollet thought that the ratio could change due to the
ratio of reactants taken in initially.
Specifically, he was puzzled over the natural formation of
natron (a hydrated sodium carbonate) from a mixture of
limestone (calcium carbonate) and seawater (containing
sodium chloride).Reactions with the same components
yielded an inverse product.
Works Cited
 http://scienceworld.wolfram.com/biogra
phy/Lavoisier.html
 http://science.howstuffworks.com/diction
ary/famous-scientists/chemists/josephlouis-proust-info.htm
 http://www.britannica.com/EBchecked/t
opic/62812/Claude-Louis-Berthollet