October 8, 1850, in Paris (France) – September 17, 1936, in Miribel-les-Échelles (France)
His father, an engineer by profession, was a great influence on him since he participated in the birth of French industry, especially aluminum, in the introduction of the Martin-Siemens process in the steel industry and in the development of rail transport.
Order and law was a determining factor in his strict upbringing. He studied at the Collègue Rollin in Paris and, after studying Special Mathematics for a year, in 1869 he entered the L'École Poytecnique just as his father had done and, like all the students, he was appointed sub-lieutenant and participated in the Siége de Paris (Site of Paris).
In 1871, he began studying at L'École des Mines in Paris (he finished the third of his promotion) and there he regularly attended the laboratory at L'École Normale Supérieure of Henri Sainte-Claire Deville, a great chemist of the time.
Despite his training as an engineer, he preferred to pursue a career as a research professor in chemistry rather than go into industry.
In 1887, he was elected director of the General Chemistry department at L'École des Mines de Paris. Since he played until he retired.
He was the successor of Paul Schützenberger in the position of director of Mineral Chemistry at the Collège de France and, later, at the Sorbonne, he succeeded Henri Moissan.
He investigated the phenomena of combustion; the theory of chemical equilibria, the measurement of high temperatures and dissociation phenomena; the properties of metal alloys; iron alloys; the methods and general laws of Analytical Chemistry; the general laws of Chemical Mechanics; silica and its compounds; some practical applications of the fundamental principles of chemistry and the properties of metals and some alloys.
In 1907, he was made a member of L'Académie des Sciences, after four unsuccessful attempts.
In chemistry, Henry Le Châtelier is known for the chemical principle that bears his name and which is stated:
“If a chemical system in reversible equilibrium experiences a change in concentration, temperature, or pressure, the equilibrium of the system will be modified in order to minimize that change”
That is, if the partial pressure of a compound increases to the left of an equilibrium reaction, it will tend to shift to the right to decrease the pressure.
Related to his principle, he also investigated the variation of the solubility of salts in an ideal solution.
He published about 30 works on these subjects between 1884 and 1914.
Throughout his career he was also dedicated to industry and even founded a technical magazine for the metallurgy sector and published several books.
He was a member of the Legion of Honor (1887); raised to the rank of Officer (1908), then Commander (1919) and finally Grand Officer (1927) and received the Royal Society's Médaille Davy (1916).
As a curiosity, there is a silica glass mineral called lechatelierite in his honor.