- Person
- Fritz Haber
- Lived
- 1868–1934
- Field
- Chemistry
- From
- German
The story
Measuring acidity, or pH, is one of the most common tasks in science, medicine, farming and industry. Yet the concept of pH itself is little more than a century old: the Danish chemist Søren Sørensen introduced it in 1909.
Fritz Haber, born in 1868 into a Jewish family in Breslau, spent the years from 1894 to 1911 at the technical university in Karlsruhe, where he taught himself the young science of physical chemistry and became a leading electrochemist. He studied the electrical potentials that arise at the boundary between solids and solutions. His research on the electrolysis of solid salts in 1904 confirmed that Faraday's laws hold for crystalline salts and helped lay a theoretical basis for the glass electrode.
In 1906 the physiologist Max Cremer had found that the electrical potential between liquids on either side of a thin glass membrane depends on their acidity. Haber took up the idea. In January 1909 he and Zygmunt Klemensiewicz reported their research on the glass electrode to the Karlsruhe Chemical Society, and they published it that year in the Zeitschrift für physikalische Chemie. His Nobel biography credits Haber, in collaboration with Cremer, with inventing the glass electrode for measuring the acidity of a liquid, and notes that it is now widely used.
The same work led Haber to make the first experimental investigations of the potential differences between solid electrolytes and their solutions, which were of great interest to physiologists. He also studied the quinone–hydroquinone equilibrium at an electrode, laying the foundations for Biilmann's quinhydrone electrode, another tool for measuring acidity.
Later researchers, such as W. S. Hughes in 1922, deepened the understanding of how the glass responds to hydrogen ions. Measuring pH is now the most common use of glass electrodes, which are an important part of the instruments of analytical chemistry, and versions sensitive to other ions work on the same principle. The device that began as a laboratory study in Karlsruhe became one of the everyday tools of modern science.
Why it matters
Glass-electrode pH meters are used every day in hospitals, laboratories, water treatment, agriculture and food production.
About Fritz Haber
Nobel chemist whose ammonia synthesis made the fertilisers that feed billions, who also led Germany’s WWI poison-gas programme, and who was driven out by the Nazis.
More about Fritz Haber
- Fritz Haber's surface idea inspired LangmuirFritz Haber observed that the adsorbing power of a solid can come from unsaturated valence forces on its surface, an idea on which Irving Langmuir founded his theory of adsorption.
- Haber–Bosch fertiliser helps feed half the worldScaled up by Carl Bosch from 1913, Fritz Haber's ammonia process made cheap fertiliser possible. Food grown with it is estimated to support nearly half the world's population.
- Fritz Haber rebuilt his institute into a world centreIn the 1920s Fritz Haber reorganised his Berlin-Dahlem institute, giving directors such as James Franck and Michael Polanyi full freedom and making it an international centre of science.
- Fritz Haber linked electrochemistry to industryFritz Haber's 1898 textbook on technical electrochemistry and his discovery that controlling electrode potential yields specific products became classics of the field.
- Fritz Haber invented a whistle to protect minersIn 1913 Fritz Haber unveiled a firedamp whistle that used sound to warn miners of explosive methane, and he also devised a quartz-thread gauge for very low gas pressures.
- Fritz Haber made ammonia from the air in 1909In 1909 Fritz Haber and Robert Le Rossignol became the first to synthesise ammonia from nitrogen and hydrogen, solving a problem chemists had pursued for decades.
- Fritz Haber wrote a model book on gas reactionsFritz Haber's 1905 book Thermodynamics of Technical Gas Reactions was later regarded as a model of accuracy and critical insight in chemical thermodynamics.
- Fritz Haber resigned rather than dismiss his Jewish staffOrdered by the Nazis in 1933 to dismiss Jewish employees, Fritz Haber tried to delay their departures until he could find them places, then resigned himself.
Sources
- Fritz Haber: Biographical NobelPrize.org
- Fritz Haber Wikipedia
- Glass electrode Wikipedia
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