1. Lavoisier, Proust, Berthollet, and the Laws of Conservation of Mass and Definite Proportions Madeleine Scriber And Sydney Tress

2. Antoine Lavoisier

3. Lavoisier Biography August 26, 1743- May 8, 1794 Born in Paris, France Studied at College des Quatre Nations Attended College Mazarin Colleague: Guillaume-Francois Rouelle Won a prize on lighting the streets of Paris Designed a new method for preparing saltpeter. Studied the nature of combustion and devised a system of naming elements

4. Lavoisier Biography Continued “Father of Modern Chemistry” He published a documentary, Traité Elémentaire de Chimie Denied the existence of Phlogiston Establishment of the Law of Conservation of Mass

5. Lavoisier Lab Apparatus Replica of Lavoisier's calorimeter, a piece of equipment for measuring the amount of heat produced by combustion Used to investigate combustion. Lavoisier called the gas oxygen Replica of apparatus for hydrogen combustion experiment, made from a sketch by Madame Lavoisier

6. Lavoisier and Berthollet They proposed new names for elements. The need for an international nomenclature consistently reflecting the composition of substances became aware to Lavoisier. Before Lavoisier the language used in chemical texts was full of inconsistencies, imprecision and double meanings.

7. Joseph Proust

8. Proust Biography September 26, 1754- July 5, 1826 Born in Angers, France Taught Chemistry School at Sergovia and the University of Salamanca in Spain Chemical analysts Discovered that each pure compound has its own characteristic elemental composition. He put hydrogen into the realm of science was disproving Berthollet with the law of definite proportions

9. Proust Biography Continued first accumulated conclusive evidence for it in a series of researches on the composition of many substances, especially the oxides of iron Law of Constant Proportions: known for helping prove the idea that every pure chemical compound consists of elements in a definite proportion Rival: Berthollet

10. Claude Louis Berthollet

11. Berthollet Biography December 9, 1748- November 6, 1822 Born in Talloires, France Started his studies at Chambéry and then in Turin where he graduated in medicine. Active participant of the Academy of Science in 1780 Rival: Proust He first produced a modern bleaching liquid in 1789 in his laboratory in Paris, France, by passing chlorine gas through a solution of sodium carbonate.

12. Berthollet Biography Continued Known for his scientific contributions to theory of chemical equilibrium. First to demonstrate the bleaching action of chlorine gas. First determined the elemental composition of ammonia. First proved that chemical reactions and affinities are dependent upon physical factors, such as mass and temperature.

13. Berthollet Lab Apparatus Burette, a common laboratory apparatus for carrying out titration, an important experimental technique in equilibrium and analytical chemistry.

14. Laws of Conservation of Mass and Definite Proportions Stated that in a chemical reaction, matter is neither created or destroyed It brought to the end the misconception of the existence of Phlogiston. An entire class of substances does not follow this rule. The compounds are called non-stiochiometric compounds. also named berthollides in his honor.

15. Bibliography "Antoine Lavoisier." Antoine Lavoisier. N.p., n.d. Web. 23 Oct. 2013.. "Joseph Proust." Joseph Proust. N.p., n.d. Web. 24 Oct. 2013.. "Claude-Louis Berthollet (French Chemist)." Encyclopedia Britannica Online. Encyclopedia Britannica, n.d. Web. 24 Oct. 2013.. Dingrando, Laurel. "Law of Definite Proportions." Chemistry: Matter and Change. New York, NY: Glencoe/McGraw-Hill, 2005. 75. Print.