Joseph Louis Proust Experiments and Discoveries

JOSEPH LOUIS PROUST: (1754 – 1826)

JOSEPH LOUIS PROUST: (1754 – 1826)

Joseph Louis Proust was a French Chemist. He was the first scientist to think of chemical compounds.

Proust discovered The Law of Constant Proportions in 1794, he stated that “A chemical compound always contains the same elements combined together in the same proportion by mass”.

The Law of Constant Proportions are also known as the Law of Definite Proportions and Law of Constant Composition.

·Proust law is independent of source, method of preparation of compound and amount of mass.

·Proust did experiment to prove his law with copper carbonate, the two tin oxides, and the two iron sulfides.

·Proust did experiment with artificial copper carbonate and comparing it to natural copper carbonate. With this, he showed that each had the same proportion of weights between the three elements copper, carbon and oxygen.

·Proust published his law in 1794, his law was controversy with French chemist Claude-Louis Berthollet, who claimed that a chemical compound could possess different chemical compositions. Proust showed that the compounds processed by Berthollet were actually not compounds and chemical mixtures. Therefore, these compounds are named bertolidos, and published his hypothesis in 1799. The law was not accepted until 1811. Swedish chemist Jons Jacob Berzelius established the relationship between Proust's law and Dalton's theory in 1811.

·For example, the formation of water always contains hydrogen and oxygen together in the ratio of 1:8 by mass.

·Proust experiments with inorganic compounds - metal sulfates, sulfides, and metallic oxides.

·Proust works include research in metallurgy, explosives, nutritional chemistry, and blue of Prussia.

·Proust was the first to identify the sugar in grapes as glucose in 1799. He showed the sugar in grapes is identical to that found in honey.

·Proust helped to Jean Francois Pilatre de Rozier develop of the first hot air balloons in 1784.

·Proust’s law influenced the Law of conservation of mass.

·During Proust's time, we had no idea of the atom.

·John Dalton used Proust’s law in the formulation of his atomic theory.