Today In Science History – October 8 – Henry-Louis Le Chatelier


Le Chatelier

Henry Le Chatelier (1850-1936) French chemist

October 8 is Henry-Louis Le Chatelier’s birthday. Le Chatelier is the French chemist best known for Le Chatelier’s Principle.

Le Chatelier’s Principle is a principle which deals with chemical systems in equilibrium. It states:
If the temperature, concentration, volume or partial pressure of a chemical system at equilibrium changes, the equilibrium of the system will change to compensate for the change.

This principle is useful for predicting the effects on a chemical system if any of these variables are changed. Another useful aspect is determining which variables to change to alter the progress of an ongoing reaction to the desired result. Perhaps by changing the temperature, the chemist can maximize the yield of one of the reactions.

One product of his research was coming very close to discovering the Haber Process for synthesizing ammonia. He was attempting force nitrogen and hydrogen gases to mix at high temperature and pressure in the presence of iron. The nitrogen/hydrogen mixture was forced into a compressor and heated using a platinum wire. During the heating process, the apparatus exploded violently, almost killing one of his assistants. He discovered the explosion was due to air mixing with his gas mixture, but he did not continue the experiment. Fritz Haber would develop a method of synthesizing ammonia in less than five years that would be similar in method to Le Chatelier’s experimental design. Le Chatelier remarked towards the end of his life that the discovery of ammonia synthesis ‘slipping through his fingers’ was the biggest blunder of his scientific career.

Although Le Chatelier is best known for his chemical work, he was also a metallurgist and materials engineer. He conducted extensive research in the study of cement, metals, and alloys. He also designed instruments like the thermocouple to measure high temperatures needed to work with metals.

Notable Science Events for October 8

1927 – César Milstein was born.

Milstein was an Argentine biochemist who shares the 1984 Nobel Prize in Medicine with Niels K. Jerne and Georges Köhler for their work on the immune system and the discovery of monoclonal antibodies. Together with Köhler, he developed the hybridoma technique to produce monoclonal antibodies. They fused antibody producing B-lymphocyte cells with tumor cells to produce a hybridoma that continuously produced antibodies. This technique is used in the commercial development of diagnostic tests and new drugs.

1918 – Jens Christian Skou was born.

Skou was is a Danish biochemist who was awarded half the 1997 Nobel Prize in Chemistry for the discovery of the first ion-transporting enzyme. The enzyme he discovered is called sodium-potassium-activated adenosine triphosphatase, or more simply, Na+-K+ ATPase.This enzyme acts as a pump that exchanges sodium ions for potassium ions in plasma membranes of animal cells.

1917 – Rodney Robert Porter was born.

Porter was an English biochemist who shares the 1972 Nobel Prize in Medicine with Gerald Edelman for their independent determination of the chemical structure of antibodies. They both broke the immunoglobulin G (IgG) antibody molecule into smaller pieces and determined the structures of the pieces. They then compiled the smaller structures and determined the complete larger structure.

1904 – Clemens Alexander Winkler died.

Clemens Alexander Winkler

Clemens Alexander Winkler (1838 – 1904)

Winkler was a German chemist who discovered and isolated the element germanium. Germanium was a hole in Mendeleev’s periodic table that he named ekasilicon. Winkler discovered the new element while investigating the mineral argyrodite that was mainly composed of sulfur and silver.

1883 – Otto Heinrich Warburg was born.

Otto Heinrich Warburg

Otto Heinrich Warburg (1883 – 1970) Credit: German Federal Archives 1931.

Warburg was a German biochemist who was awarded the 1931 Nobel Prize in Medicine for his discoveries into cellular respiration or how living cells take up oxygen. He identified the family of enzymes called cytochromes where the iron-containing heme group binds oxygen. He also isolated the first flavoprotein, flavine that participates in dehydrogenation reactions in cells.

1873 – Ejnar Hertzsprung was born.

Hertzsprung was a Danish astronomer who classified types of stars by surface temperature or color to their brightness. He produced the Hertzsprung-Russell diagram with Henry Russell to graphically illustrate the spectral class of stars based on temperature and absolute magnitude. This chart is used in the study of stellar evolution. He also created a luminosity scale of Cepheid variable stars.

1850 – Henry-Louis Le Chatelier was born.

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