History
The concept of a reversible reaction was introduced by Berthollet in 1803, after he had observed the formation of sodium carbonate crystals at the edge of a salt lake (one of the natron lakes in Egypt, in limestone):
- 2NaCl + CaCO3 → Na2CO3 + CaCl2
He recognized this as the reverse of the familiar reaction
- Na2CO3 + CaCl2→ 2NaCl + CaCO3
Until then, chemical reactions were thought to always proceed in one direction. Berthollet reasoned that the excess of salt in the lake helped push the "reverse" reaction towards the formation of sodium carbonate.
In 1864, Waage and Guldberg formulated their law of mass action which quantified Berthollet's observation. Between 1884 and 1888, Le Chatelier and Braun formulated Le Chatelier's principle, which extended the same idea to a more general statement on the effects of factors other than concentration on the position of the equilibrium.
Read more about this topic: Reversible Reaction
Famous quotes containing the word history:
“What has history to do with me? Mine is the first and only world! I want to report how I find the world. What others have told me about the world is a very small and incidental part of my experience. I have to judge the world, to measure things.”
—Ludwig Wittgenstein (1889–1951)
“The reverence for the Scriptures is an element of civilization, for thus has the history of the world been preserved, and is preserved.”
—Ralph Waldo Emerson (1803–1882)
“The history of medicine is the history of the unusual.”
—Robert M. Fresco, and Jack Arnold. Prof. Gerald Deemer (Leo G. Carroll)