Tuesday, July 6, 2010
Joseph Louis Proust.
PROFILE
Louis Proust (Joseph Louis Proust)
Info
He was born in Angers, France. His father served as an apothecary in Angers. Joseph studied chemistry in his father’s shop and later came to Paris where he gained the appointment of apothecary in chief to the Salpetriere. He also taught chemistry with Pilâtre de Rozier, a famous astronaut.
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 when Napoleon invaded Spain, they burned Proust's laboratory and forced him back to France. On July 5 1826 he died in Angers, France.
Proust's best known work was derived from a controversy with chemist C.L. Berthollet. Berthollet did not believe that substances always combine in constant and definite proportions as
Proust did. Proust eventually was able to prove Berthollet wrong in 1799 and published his own hypothesis.Proust based his work on the study of copper carbonate reactions performed in the laboratory.
He analytically studied the two tin oxides and the two iron sulfides, proving that had different compositions and that there were no substances with intermediate composition.
His laboratorial tests showed that the variable composition oxides, studied by Berthellot, were hydrated products. He also performed a series of researches to characterize different types of sugars, present in vegetable products.
Brief History
SOURCES
http://en.wikipedia.org/wiki/Joseph_Proust
http://www.chem.lsu.edu/lucid/courseinfo/chem1002/Image28.gif
https://reich-chemistry.wikispaces.com/Fall.2008.MMA.Owens.Timeline
http://www.answers.com/topic/joseph-proust
Louis Proust (Joseph Louis Proust)
Info
- Born on September 26, 1754
- Died on July 5, 1826
- He was a French Chemist
He was born in Angers, France. His father served as an apothecary in Angers. Joseph studied chemistry in his father’s shop and later came to Paris where he gained the appointment of apothecary in chief to the Salpetriere. He also taught chemistry with Pilâtre de Rozier, a famous astronaut.
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 when Napoleon invaded Spain, they burned Proust's laboratory and forced him back to France. On July 5 1826 he died in Angers, France.
Proust's best known work was derived from a controversy with chemist C.L. Berthollet. Berthollet did not believe that substances always combine in constant and definite proportions as
Proust did. Proust eventually was able to prove Berthollet wrong in 1799 and published his own hypothesis.Proust based his work on the study of copper carbonate reactions performed in the laboratory.
He analytically studied the two tin oxides and the two iron sulfides, proving that had different compositions and that there were no substances with intermediate composition.
His laboratorial tests showed that the variable composition oxides, studied by Berthellot, were hydrated products. He also performed a series of researches to characterize different types of sugars, present in vegetable products.
Brief History
The 19th century (1801–1900) was a period in history marked by the collapse of the Spanish,Portuguese, Chinese, Holy Roman and Mughal empires. This paved the way for the growing influence of the British Empire, the German Empire and the United States, spurring military conflicts but also advances in science and exploration.The 19th century was an era of invention and discovery, with significant developments in the fields of mathematics, physics, chemistry, biology, electricity, and metallurgy that lay the groundwork for the technological advances of the 20th century.
What is The Law of Definite Proportions?
The Law of Definite Proportions is a scientific law discovered by Joseph Proust. It states that the composition of chemical compounds is proportionate regardless of the size of the sample. Though the principle has been found to be non-universal in the past 50 years due to increased testing capabilities, it still stands as a basic foundation of chemical composition.
- Joseph Proust, a French chemist, declared the law of definite proportions in 1806 after studying the principle for almost 10 years. It was a revolutionary concept among the scientific community and was opposed at first by other chemists. The adversaries of Proust's find believed that compounds could combine in any amount. It wasn't until John Dalton unveiled the atomic theory--that all compounds are made up of atoms--that credence was given to Proust's assertions.
Here are, however, exceptions to the Law of Definite Proportions. An entire class of substances does not follow this rule. The compounds are called non-stoichiometric compounds.
Non-stoichiometric compounds
- also called Berthollides, after Berthollet.
- are chemical compounds with an elemental composition that cannot be represented by a ratio of well-defined natural numbers, and therefore violate the law of definite proportions.
At the end of the 18th century, however, when the concept of a chemical compound had not yet been fully developed, the law was novel. In fact, when first proposed, it was a controversial statement and was opposed by other chemists, most notably Proust's fellow Frenchman Claude Louis Berthollet, who argued that the elements could combine in any proportion.The very existence of this debate underscores that at the time, the distinction between pure chemical compounds and mixtures had not yet been fully developed.
The law of definite proportions contributed to, and was placed on a firm theoretical basis by, the atomic theory that John Dalton promoted beginning in 1803, which explained matter as consisting of discrete atoms, that there was one type of atom for each element, and that the compounds were made of combinations of different types of atoms in fixed proportions.
One of the fundamental observations of modern chemistry, the law of definite proportions states that, in a pure compound, the elements combine in definite proportions to each other.
An equivalent statement is the law of constant compostion, which states that all samples of a given chemical compound have the same elemental composition.
For example, oxygen makes up 8/9 of the mass of any sample of pure water, while hydrogen makes up the remaining 1/9 of the mass.
Along with the law of multiple proportions, this forms the basis of stoichiometry.
This observation was first made by the French chemist Joseph Proust based on several experiments conducted between 1797 and 1804. In most of these experiments, Proust reacted several of the elements with oxygen and observed that the oxygen content of the product of these reactions was always fixed at one or two values, rather than displaying a broad range of possible values. For example, Proust measured that the product of iron and oxygen might contain 27% oxygen or 48% oxygen, but not an intermediate composition, or that the product of copper and oxygen might contain 18% oxygen or 25% oxygen, but not an intermediate composition.
He is the French chemist who proved that the relative quantities of any given pure chemical compound’s constituent elements remain invariant, regardless of the compound’s source. This is known as Proust’s law, or the law of definite proportions (1793), and it is the fundamental principle of analytical chemistry. Proust also carried out important applied research in metallurgy, explosives, and nutritional chemistry.
PHOTOS
SOURCES
http://en.wikipedia.org/wiki/Joseph_Proust
http://www.chem.lsu.edu/lucid/courseinfo/chem1002/Image28.gif
https://reich-chemistry.wikispaces.com/Fall.2008.MMA.Owens.Timeline
http://www.answers.com/topic/joseph-proust
http://en.wikipedia.org/wiki/Law_of_definite_proportions
Group 2
Lacanilao, Lagaya, Legazpi, Manacsa, Marquez.
Group 2
Lacanilao, Lagaya, Legazpi, Manacsa, Marquez.
Aristotle and Leucippus
Group 1(MonoBlocks Group)
~ATOMS: THE GREEK IDEA~
We hear something about atoms almost everyday. The twentieth century brought us into the Atomic Age. Why should we care about something as tiny as an atom? Because our world is made up of atoms, and atoms are a part of all we do. Everything is made of atoms including you and me.
Guess who?
LEUCIPPUS
PROFILE:
- Leucippus was a shadowy figure, as his dates are not recorded and he is often mentioned in conjunction with his more well-known pupil Democritus.
- He was the first Greek to develop the theory of atonism— the idea that everything is composed entirely of various imperishable, indivisible elements called atoms — which was elaborated in far greater detail by his pupil and successor, Democritus.
- He was most probably born in Miletus, although Ajbdera andElea are also mentioned as possible birthplaces.
THE IDEA:
There must ultimately be tiny particles of water that could not be subdivided.
Example:
From a Distant, the sand on the beach looked continuous, but it is to be made up of tiny grains.
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Guess who?
ARISTOTLE
PROFILE:
- Aristotle was born in Stageira, Chalcidice, in 384 B.C.
- A student of Plato and teacher of Alexander the Great.
- He was trained first in medicine, and then in 367 he was sent to Athens to study philosophy with Plato.
- Though a brilliant pupil, Aristotle opposed some of Plato's teachings, and when Plato died, Aristotle was not appointed head of the Academy.
- His writings cover many subjects, including physics, metaphysics, poetry, theater, music, logic, rhetoric, politics, government, ethics, biology, and zoology.
THE IDEA:
Considered the greatest of the ancient Greek philosophers, had considered that matter was continuous-infinitely divisible- rather than atomistic-consisting of fundamental particles that are themselves indivisible and the people of that time had no way to determine which view of matter seemed more logical and reasonable, and so Aristotle's view prevailed for 2000 years, even though it was wrong.
REFERENCES:
BOOK:
Chemistry for Changing Times (book)
WEBSITES:
http://en.wikipedia.org/wiki/Aristotle
http://en.wikipedia.org/wiki/Leucippus
http://www.ucmp.berkeley.edu/history/aristotle.html
VIDEOCLIP:
http://video.google.com/videoplay?docid=-2187430983017163849#
Group Members:
Dianne Ang
Androse Ansaldo
Micah Antonio
Oya Bautista
Angela Cansana
Angela Cansana
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