University of Kansas, Lawrence, Kansas, United States
Kraus entered the University of Kansas in 1894. In his junior year he coauthored a paper on spectroscopy, and he received his bachelor’s degree in engineering in 1898.
Gallery of Charles Kraus
Massachusetts Institute of Technology, Cambridge, Massachusetts, United States
From 1904 Kraus became a research assistant at the Massachusetts Institute of Technology, where he received his doctorate in chemistry in 1908.
Career
Achievements
Membership
National Academy of Sciences
2101 Constitution Ave NW, Washington, DC 20418, United States
Kraus was a member of the National Academy of Sciences.
Awards
Willard Gibbs Award
1935
Kraus was awarded the Willard Gibbs Award in 1935.
Franklin Medal
1938
Kraus was awarded the Franklin Medal in 1938.
Navy Distinguished Public Service Award
1948
Kraus was awarded the Navy Distinguished Public Service Award in 1948.
University of Kansas, Lawrence, Kansas, United States
Kraus entered the University of Kansas in 1894. In his junior year he coauthored a paper on spectroscopy, and he received his bachelor’s degree in engineering in 1898.
Charles August Kraus was an American chemist and professor of chemistry at Clark University and Brown University. He is known for his work on the electrical conductance of liquid ammonia alkali metal solutions which contributed to the development of the concept of solvated electron.
Background
Charles August Kraus was born on August 15, 1875, in Knightsville, Indiana, United States. He was the son of John H. Kraus and Elizabeth Schaefer. Although he spent most of his childhood on a Kansas farm, Kraus developed a strong interest in physics and electrical engineering.
Education
Kraus entered the University of Kansas in 1894. In his junior year, he co-authored a paper on spectroscopy, and he received his bachelor’s degree in engineering in 1898. After a year’s further study at Kansas and a year as a research fellow at Johns Hopkins University. From 1904 he became a research assistant at the Massachusetts Institute of Technology, where he received his doctorate in chemistry in 1908.
Kraus served as an instructor of physics at the University of California from 1901 until 1904. After graduation, he remained at MIT as a research associate (1908-1912) and an assistant professor of physical-chemical research (1912-1914). In 1914 he was named professor of chemistry and head of the chemical laboratory at Clark University, where he remained for nine years.
Around 1920 Thomas Midgley, Jr., and T. A. Boyd of General Motors discovered that tetraethyl lead would reduce engine knocking when added to gasoline. As a consultant to Standard Oil Company of New Jersey, Kraus was asked to design an economical quantity synthesis of this substance. After a three-month intensive study with Conrall C. Callis late in 1922, Kraus succeeded in producing a reaction between a lead-sodium alloy and ethyl chloride under high pressures and relatively low temperatures followed by steam distillation. This discovery permitted the automobile industry to develop high compression engines.
He became a professor of chemistry and director of chemical research at Brown University in 1924. Although he retired from the position in 1946, he continued his research and was working on a book when he died in 1967 at the age of ninety-one. During World War I he was active in government service. During World War II he worked with the navy and served as a consultant to the Manhattan Project. Specifically, he was instrumental in working out a process for purifying uranium salts.
Kraus’ studies in chemical research began at the University of Kansas, where Hamilton P. Cady and Edward C. Franklin became interested in liquid ammonia solutions. Kraus was attracted by the opportunities that appeared in the field, especially by the study of solutions of the alkali metals. Using the glassblowing experience he had gained in Germany, Franklin, in conjunction with Kraus, published eight papers between 1898 and 1905, dealing with such problems as the solubility of substances in liquid ammonia, the molecular rise in the boiling point of a solution of a solute in liquid ammonia as the molal concentration of the solution is increased; and various physical properties of the solutions.
Continuing his research on liquid ammonia at MIT, Kraus published a series of articles (beginning in 1907). He reported that alkali and alkaline earth metals could form solutions with ammonia. Highly concentrated solutions would behave like metals while dilute solutions would resemble ionic solutions of salts. The dilute solutions ionize to give the normal positive metal ion and negative electrons, the latter associated with large amounts of ammonia.
At Clark University, Kraus studied other physical properties of metal ammonia solutions, notably density, conductivity, and vapor pressure. His results indicated beyond any doubt that alkali metals do not form compounds with ammonia, but alkaline earths do form compounds by combining with six molecules of ammonia to produce metal-like ammoniates.
His interest in radicals that exhibit metallic properties led to studies of alkyl mercury and ammonium and substituted ammonium groups. He then turned to work on organic radicals bonded to group four metals. He published over twenty-five papers on these metal-organic systems; many of the studies were carried out in liquid ammonia solutions because of the water or air sensitivity of most of the compounds.
Further studies at Clark and Brown concerned the electrical properties of substances dissolved in solvents of very low dielectric constant such as benzene, dioxane, and ethylene dichloride. Of particular interest are his studies of large anions and cations, which have led to a clearer picture of the nature of electrolyte solutions.
Membership
Kraus was a member of the National Academy of Sciences.
National Academy of Sciences
,
United States
Personality
Gilbert N. Lewis remarked on Kraus’ “extraordinary experimental skill” in designing and constructing glass apparatus, which was largely responsible for his successful studies.
Connections
Kraus married Frederica Feitshans on June 9, 1902. They had four children.