Joseph louis proust biography images

Joseph louis proust atomic theory

He was best known for his discovery of the law of definite proportions in , stating that chemical compounds always combine in constant proportions. His father served as an apothecary in Angers. But when Napoleon invaded Spain, they burned Proust's laboratory and forced him back to France. On 5 July he died in Angers, France. The mineral proustite Ag 3 AsS 3 is named in his honour.

Proust's largest accomplishment in the realm of science was disproving Berthollet [ 2 ] with the law of definite proportions , which is sometimes also known as Proust's Law. He did this by making 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 involved Cu , C , O.

There 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 , or Berthollides, after Berthollet. The ratio of the elements present in the compound can fluctuate within certain limits, such as for example ferrous oxide.