Edward C. Fuller
Beloit College Beloit, Wisconsin
A Redesigned Four-Year Curriculum in Chemistry
The nast seven vears have witnessed a dealing with various spate of papers in THIS JOURNAL approaches to modernizing rollegiate instruction in rhemistry. Reports of symposia sponsored by the Division of Chemical Education a t national meetings of the ACS on analytical chemistry (1-3) have been supplemented by related articles ( 4 4 ) appearing individually. Separate articles dealing with the teaching of inorganic and general chemistry (7-11) have been the forerunners of the report on a symposium (12) a t a national meeting. Reports of symposia on the teaching of radiochemistry (IS) and of hiochemistry (14) to undergraduates have also appeared. The functions of the seminar (16) and of course work in chemical literature (16) have been discussed. The special needs in general (17,18) and in physical (19) chemistry of students not majoring in chemistry have been considered. Modernizing individual courses has led to more extensive revisions of the four-year curriculum. Editorials in THIS JOURNAL (20, 21) stimulated the holding of a symposium (22) and two conferences (23, 24) on this broader approach. From studies of these papers, three major trends become apparent: (1) Understanding mid-twentieth century chemistry increasingly demands a sound foundat,ion in some aspects of physics; (2) There has been a renascence in inorganic chemistry largely stimulated by greater understanding of the nature of chemical bonds; (3) Analytical chemistry is becoming more closely correlated with physical chemistry, particularly in the field of instrumental methods of analysis. It is also apparent that chemistry is becoming increasingly important to students of biology and geology as attested by the rapid growth of biochemistry and geochemistry. We need, therefore, to attract more students majoring in these sciences into our chemistry courses. With t,hese trends in mind as guiding principles, the chemistry faculty at Beloit College redesigned the curriculum as described subsequently. Though we recognized the st,imulation of interest that often arises from giving new names to courses, we felt that we could achieve the modernization of our curriculum more effectively by putting some new wine in the old bottles of inorganic, analytical, organic, and physical chemistry. We have also mixed some of the old vintages to yield what we believe to be a headier intellectual brew.
Based on a paper presented before the Division of Chemical Education at the 140th meeting the ACS in chicago,september, 1961.
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Journal of Chemical Educofion
First Course Combined wifh Physics
Our first course in chemistry is designed to m e t t,he needs of all students who plan to major in the biological or physical sciences. The primary purpose of this course is to get the student to interpret the chemical behavior of matter in terms of processes involving atoms and molecules both as individuals and in groups. To do this he must understand the kinet,icmolecular concept of matter, the subatomic structure of matter, and the ways in which atoms and molecules interact with thermal, electric, and radiant energy. Such understanding requires a working knowledge of several basic principles of physics. These may be summarized briefly as follows: dynamics of a part,icle including uniform rectilinear motion, uniform accelerat,ion, uniform circular motion, central accelerat,ion, Newton's laws of motion, linear and angular momentum; energetics of a particle including kinetic and potential energy, work, heat as a mode of motion; elect,ricity and magnetism including unit charge and unit, pole, the field concept, work done in moving a charge through an electric field, effects of a magnetic field on a moving charge; wave motion and electromagnet,ic radiation including the nature of waves (interference, etc.), the quantization of radiat,ion, and the wareparticle concept. Accordingly, our int,roduction to college chemistry is combined with elementary college physics in a coursc called "Basic Concepts of Physics and Chemistry." This course begins with the kinematics and dynamics of moving bodies as a hasis for developing the concepts of work and energy. That thermal energy is a mode of motion is brought out in studying changes in the states of matter and in the kinet,ic-molecular modelfor matter. The atomicity of matter and the concept of relative atomic mass arc derived from mass relations in chemical reactions and serve to establish the relations between atoms and molecules. St,at,icelectricity, flowing elect,ricity, and electric fields are studied to reveal the nat,ure of electric energy and work. Electrochemical phenomena such as electrolytic conduction, electrolysis, and chemical reactions as sources of electric energy are explained in terms of ionic reactions including simple oxidation-reduction systems. Electric work is studied as a manifest,ation of free energy (chemical uotential energy). - The seconTsemester of the combined physicschemistry course begins with a study of magnetic fields, waves, and electromagnetic radiation as a basis for understranding the nature of the fundamental particles r of matter and the nuclear atom. The ~ o h concept of the hydrogen at,om is usrd as a bridge to t,he simplest
aspects of the wave mechanical concept of electron orbitals in atoms. The electron configurations of the elements are considered in terms of the permitted vdues of quantum numbers and thePauli exclusion principle. The periodic table is considered in terms of the elements' physical and chemical properties and the configurations of their electrons. The differences in the properties of various aggregates of atoms are elucidated in terms of ionic, covalent, and metallic bonds, using the atomic orbital approach and the concept of relative electronegativity The geometry and the properties of molecules and crystals are related to the orientations of pure and hybridized orbitals and the non-directional character of ionic and metallic bonds. The contributions of dipoles, induced dipoles, and hydrogen bridges to handing and structure are also discussed. Consideration of heats of reaction and of formation leads to the idea of bond energy and bond length as measures of the stabilities of compounds. The course concludes with a brief consideration of rates, activation energies, and mechanisms of reactions followed by an introdurtion to nuclear transformations. Other Fundamental Courses
In his sophomore year a student majoring in chemistry takes two semest,ers of organic chemistry and a one-semester course combining qualitative and quantitative analysis. In organic chemistry, aliphatic and aromatic compounds are studied together and much emphasisis placed on modern theoretical interpretations of reaction mechanisms. Ionic and free radical characteristics are considered and the preferred reaction is identified in terms of the most stable intermediates. Energy relationships are treated in a qualitative manner but the concepts of bond energies, activation energy, and heats of reaction are utilized. The concept of resonance is used to explain organic structures but the atomic orbital approach is employed for the simplest cases. Laboratory work includes basic techniques and simple preparations in the first semester followed by more complicated syntheses and qualitative organic analysis in the second semester. The sophomore course in qualitative and quantitative analysis emphasizes separation processes and their use in qualitative identification and quantitative determination of substances present in mixtures and compounds. Classroom discussions of theories concerning separations and equilibria in aqueous systems are supplemented by laboratory work involving separations by precipitation, chromatography, ion exchange, and the use of complexing reagents. Quantitative determinations involve some representative volumetric and gravimetric analyses, acid-base systems, and the measurement of pH-always with emphasis on the differences between real and ideal solutions.
A three-semester seqnence in physical chemistry begins in the fall of a chemistry major's junior year. The first semester is an introduction to the subject which will enable students majoring in biology and geology to use physico-chemical approaches where they are appropriate to these disciplines. Understanding bhese same fundament,als will prepare the student majoring in chemistry for the more mathematically rigorous study of physiral chemistry undertaken in the
second and third semesters of the sequence. Students in this introductory course who are majoring in other sciences and who are not prepared to handle the modicum of calculus required are given special instruction in the basic concepts of this phase of mathematics. The subject matter of the introductory physical chemistry course includes the first law of thermodynamics and some of its applications to systems involving gases: liquids, solids, solutions, and their colligative properties; surface phenomena and colloids; the phase rule and electrolytic transference and conduct,ance. The second semester of physical chemistry is devoted to a more mathematical description of the properties of gases, liquids, solids, and solutions; first law of thermodynamics, enthalpy, and thermochemistry; second law and free energy; chemical equilibrium in gaseous systems; entropy and the third law; thermodynamiral approaches to equilibria in solutions and galvanic cells. In the third semester of the sequence (taken in the fall of a student's senior year), rates and mechanisms of chemical reaction, atomic and molecular strncture, particles and waves, the quantized interactions of radiant energy with matter, chemical statistics, and nuclear chemistry are studied. A course in modern inorganic chemistry is taken during the spring semester of the senior year. It includes a study of the properties of the elements in relation to atomic structure, size, and electronegativity; classification of the elements into groups; forces between atoms; complex ions and coordination compounds; and inorganic reactions in aqueous and nonaqueous systems. Correlated Laboratory Work
Laboratory work for the five semesters of instruction in analytical, physical, and inorganic chemistry has beeu planned as a correlated sequence of experiments, always emphasizing quantitative results but paying 1it.tle attention to whether the experiment involves analytical, physical, or inorganic chemistry. The lahoratory work in the sophomore course in analyt,iral chemistry has already been described. In the fall semester of the junior year a student studies a solvent and the solutions it forms by measurements of dielectric constant, electrical conductance, refractive index, viscosity, surface tension, vapor pressure, vapor density, elevation of the boiling point and depression of t.he freezing point, and liquid-vapor, liquid-liquid, and liquid-solid equilibria. In the spring semester, rmphasis is placed on thermochemical measurements (heats of combustion, ionic reaction, and solution) and the thermodynamics of electrochemical systems (single electrode potentials, hydrogen electrode, glass electrode, free energy and the equilibrium constant, potentiometry). In the fall semester of his senior year, the student does laboratory work on rates of reaction (inversion of sucrose, hydrolysis, saponification, and decomposition). He also studies the interaction of radiant energy with matter in photochemical processes and by colorimetry, spectrography, and spectrometry. In the spring semester he studies polarography, electrodeposition, coulometry, gas chromatography, reactions in evacuated systems, and radioactivity. Volume 39, Number 6, June 1962
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Requirements for the Major in Chemistry
The two semesters of physics-chemistry, the t x o semesters of organic chemistry, and the five semesters of analytical-physical-inorganic chemistry, together with a one-semester course in chemical literature, complete a major with 34 semester-hours in chemistry. A student v h o wishes to qualify for a statement from the American Chemiral Society t,hat he has fulfilled its standards for professional training RS an undergraduate will also take a minimum of *is semest,er-hours in research. The usual courses in a foreign language, mathematics, and physics are taken by all students majoring in chemistry. The author wishes to express his indebtedness to Dr. John L. Biester. Dr. Donald L. McMasters, and Dr. William E. Rice-members of the Beloit chemistry faculty who made import,ant contributions t,o the designing of the cnrrirnlum described in this paper. Literature Cited (1) Symposium: "Prol,lems in the Teaching of Instrumentsl Analysis." J. CHEM.EDUC.,33, 422ff (1956). (21 Svm~osiorn: '-Qualitative A n a l v s i s W h t ~ t .Whv. How?"
ROGEFLS, L. B., J. CHEM.EDTC.,38,455 (1961). COULD,E. S., J. CHEM.EDCC., 33, 23 (1956). MALM.L. E.. J. CHEM.EDI-c..33. 390 (1956). ~rcHo'LsoN,D. G., J. CHEM.EDI.~'., 33, Qgi ( i m ) . NECHAMKIN, H., J. CHEM.ED
