Lavoisier, Proust and Berthollet and the Laws of Conservation of Matter and Definite Proportions

1. Lavoisier, Proust and Berthollet and the Laws of Conservation of Matter and Definite Proportions Cara Scatena and Allison Schwedock

2. Lavoisier • (8/26/1743 [kingdom of france] - 5/8/1749 [paris]) • Bio: • Born into a wealthy family and with the passing of his father inherited a large sum of money • Began his schooling at the Collège des Quatre-Nations  • Studied chemistry, botany, astronomy, and mathematics • Eventually studied uder, Abbé Nicolas Louis de Lacaille, a distinguished mathematician and observational astronomer who lead Lavoisier to his interest in meteorological observation • He established the Law of Conservation of Matter. • Created many theories with combustion

3. Lavoisier • Law of Conservation of Matter- matter can neither be created nor destroyed • Demonstrated that transmutation of water to earth was not possible.  • He discovered that the total mass of the products in a chemical reaction is always the same as the total mass of the starting materials consumed in the reaction • Changed chemistry from qualitive to quantitive • Oxygen theory of combustion • He burnt phosphorus and sulfur in air, and proved that the products weighed more than the original. Therefore, the weight gained was lost from the air.  • • Methods of Chemical Nomenclature • he invented the system of chemical nomenclature that is still used today, including names such as sulfuric acid, sulfates, and sulfites.

4. Lavoisier • He attempted to take Priestley’s (his rival) credit of discovering that air is composed of two parts, and that one combines with metals to form calxes.  • He also attempting to take Priestley’s credit for discovering that the inflammable air of Cavendish which he called hydrogen, combined with oxygen to produce a dew known as water. 

5. Proust • (9/26/1754 [angers, france] - 7/5/1826 [paris]) • Bio • He was a sickly young child which would eventually interfere with his schooling at Lycée Condorcet • Despite his health fought for the french military for one year • Eventually taught chemistry in France and Spain • Closeted homosexual, whose health deteriorated as he lost family members • Was also an author who published many stories • Created Elements from water • Law of Definite proportions

6. Proust • Law of Definite Proportions- states that a chemical compound always contains exactly the same proportion of elements by mass. • proved this by accurate measurements. • showed that cupric carbonate always had 5.3 parts copper to 1 part carbon to 4 parts oxygen. • Created elements from water • His best work (LDP) is derived from controversy with CL Berthollet

7. THE CONTROVERSY • THE LAW OF DEFINITE PROPORTIONS was opposed by other chemists • most notably Proust's fellow Claude Louis Berthollet • who argued that the elements could combine in any proportion. • The existence of this debate demonstrates that, at the time, the distinction between pure chemical compounds and mixtures had not yet been fully developed. PROUST WAS RIGHT IN THE END!

8. C. L Berthollet • (12/8/1748 [talloire, france] - 11/8/1822 [Arcueil, France]) • Bio • Studied at Chambéry and then in Turin where he graduated in medicine. • Had great development in works regarding chemistry making him an active participant of the Academy of Science in 1780 -- battled with Joseph Proust ⁃ he was wrong and these incorrect solid chemical compounds that do not conform to the law are known as berthollides. -- member of physics and natural history in Egypt

9. Berthollet • Devised a chemical system of names which serves as the basis of the modern system of naming chemical compounds.  • Carried out research into dyes and bleaches and determined the composition of ammonia. • One of the first chemists to recognize the characteristics of a reverse reaction, and chemical equilibrium. • Potassium chlorate (KClO3), a strong oxidizer, is known as Berthollet's Salt.