CHAPTER 9 MIXTURES
9.7 ACTIVITY OF ANUNCHARGEDSPECIES 270
BIOGRAPHICAL SKETCH
Gilbert Newton Lewis (1875–1946)EDGAR FAHS SMITH COLLECTIONUNIVERSITY OF PENNSYLVANIA LIBRARY
Gilbert Lewis made major contributions to
several fields of physical chemistry. He was
born in Weymouth, Massachusetts. His father
was a lawyer and banker.
Lewis was reserved, even shy in front of a
large audience. He was also ambitious, had
great personal charm, excelled at both exper-
imental and theoretical thermodynamics, and
was a chain smoker of vile Manila cigars.
Lewis considered himself to be a disciple
of Willard Gibbs. After completing his Ph.D
dissertation at Harvard University in 1899, he
published several papers of thermodynamic
theory that introduced for the first time the
terms fugacity (1901) and activity (1907). The
first of these papers was entitled “A New Con-
ception of Thermal Pressure and a Theory of
Solutions” and began:a
For an understanding of all kinds of physico-
chemical equilibrium a further insight is neces-
sary into the nature of the conditions which exist
in the interior of any homogeneous phase. It will
be the aim of the present paper to study this prob-
lem in the light of a new theory, which, although
opposed to some ideas which are now accepted
as correct, yet recommends itself by its simplic-
ity and by its ability to explain several important
phenomena which have hitherto received no sat-
isfactory explanation.
His first faculty position (1905-1912) was at
Boston Tech, now the Massachusetts Institute
of Technology, where he continued work in
one of his dissertation subjects: the measure-
ment of standard electrode potentials in order
to determine standard molar Gibbs energies offormation of substances and ions.
In 1912 he became the chair of the chem-
istry department at the University of Cali-
fornia at Berkeley, which he turned into a
renowned center of chemical research and
teaching. In 1916 he published his theory of
the shared electron-pair chemical bond (Lewis
structures), a concept he had been thinking
about since at least 1902. In the course of mea-
suring the thermodynamic properties of elec-
trolyte solutions, he introduced the concept of
ionic strength (1921).
In 1923, at age 48, he consolidated his
knowledge of thermodynamics in the great
classicThermodynamics and the Free Energy
of Chemical Substancesbwith Merle Randall
as coauthor. After that his interests changed
to other subjects. He was the first to prepare
pure deuterium and D 2 O (1933), he formu-
lated his generalized definitions of acids and
bases (Lewis acids and bases, 1938), and at
the time of his death he was doing research on
photochemical processes.
Lewis was nominated 35 times for the No-
bel prize, but was never awarded it. Accord-
ing to a history of modern chemistry published
in 2008,cWilhelm Palmaer, a Swedish electro-
chemist, used his position on the Nobel Com-
mittee for Chemistry to block the award to
Lewis. Palmaer was a close friend of Walther
Nernst, whom Lewis had criticized on the ba-
sis of occasional “arithmetic and thermody-
namic inaccuracy.”d
His career was summarized by his last grad-
uate student, Michael Kasha, as follows:e
Gilbert Lewis once defined physical chemistry
as encompassing “everything that is interesting.”
His own career touched virtually every aspect of
science, and in each he left his mark. He is justly
regarded as one of the key scientists in Ameri-
can history. It would be a great omission not to
record the warmth and intellectual curiosity ra-
diated by Lewis’ personality. He epitomized the
scientist of unlimited imagination, and the joy of
working with him was to experience the life of
the mind unhindered by pedestrian concerns.
aRef. [ 103 ]. bRef. [ 104 ]. cRef. [ 35 ], Chap. 7. dRef. [ 104 ], page 6. eRef. [ 85 ].