G. F. Atkinson
University of Waterloo Woterloo. Ontario, Canada
Analytical Chemistry for Honors Applied Chemistry Students
A
good deal has been written recently about the trcnd toward decreased emphasis on analytical chemistry for undergraduates, and the simultaneously increased demand for analyticallytrained chemists ( I , # ) . This paper outlines the analytical chemistry content of a new program currently being introduced in this department, and discusses some of the rationale underlying this development. Background
The University of Waterloo had its origins in a program of cooperative (work-study) undergraduate engineering education set up in 1957. These programs involve spreading eight semesters of on-campus instruction over five years instead of the traditional four by including six "work terms" for four months each. Science departments were created to provide service teaching, and in 1959, a Faculty of Science was established, offering 3-year (General) and 4-year (Honors) programs on a conventional two semester academic year. Later, 4-year general programs were begun to meet a demand for better-trained high school science teachers. The contact with chemical industry provided by the nature of the engineering cooperative programs, as well as general statistical reports and private discussions, convinced the Department of Chemistry that industries were hiring many B.A.Sc. chemical engineers to perform chemists' functions hecause BSc. chemists were in short supply. All hut a small percentage of chemistry graduates were proceeding to further training in graduate schools, or were becoming high school teachers. Recognition of the needs of the former stream was imposing an increasingly theoretical flavor on the undergraduate program. After discussions with a number of industries, it was decided to begin an honors program to be called Applied Chemistry and to be offered on the cooperative plan. I n 1966 the first undergraduates were enrolled, and in April, 1968 the first class entered the 2B semester. The freshman intake is about 70 students. Curriculum of the Program
The first year is one of laying foundations, and is kept interchangeable for credit with the first year of other chemistry and physics programs, and with first year B. Math. (Science Options) in the Faculty of Mathematics. This makes it possible for students to change their mind without disadvantage either into or out of the Applied Chemistry program. Subjects of Year 1 are: chemistry, physics, calculus, algebra and solid geometry, numerical procedures, and English literature.
Years 2 and 3 include in their four semesters introductory courses in technical literature, analytical chemistry, radiochemistry, biochemistry, and polymer chemistry. There are two-course sequences in inorganic, organic, and physical chemistry, and in instrumental measurements. Supporting subjects include differential equations and probability and statistics from the Faculty of Mathematics; electricity and magnetism, physical optics, and electronics from the Department of Physics; and two free electives from the Faculty of Arts. Year 4 requires a core of two analytical courses, two specialized courses (corrosion and water resources engineering), two supporting subjects (computer programming and industrial economics), two free electives and a seminar. I n addition, the student chooses a two-course sequence in polymers, biochemistry and microbiology, metallurgy and ceramics, instrumentation, or catalysis and surface chemistry. The undergraduate program breaks down on a scheduled-hours basis to be 54% required chemistry, 14% physics, 13% mathematics, and 37% other (including electives). For further details, the University Calendar may be obtained from the Office of the Registrar. Analysis and lnslrumentation
I n the summary of curriculum, it is apparent that the prominent place of analysis and measurement in chemical industry has been stressed in planning the training of applied chemists. This side of the program is begun in the 2A semester with the course described in more detail later in this paper. I n this first course, instruments are not avoided, but are treated on a semi-black-box basis. The two course sequence titled Instrumental Measurements, which occurs in the 3A and 3B semesters, is intended to stress the role of the equipment in obtaining accurate analytical data. This should complement the stress on the role of personal technique in the 2A semester. The use of the term "meawrement" rather than "analysis" foreshadows a recent suggestion (3) and reflects two aspects of our planning. The first is the desire to include the sort of precise measurements of properties frequently used as analytical criteria but more often taught under a physical chemistry label to undergraduates. The second is the intention of effecting a separation of the emphasis on obtaining data (Instrumental Measurement) from an emphasis on signal processing from transducer to readout (Instrumentation). Our sequence suggests that making instruments give Volume 46, Number 8, August 1969
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answers as truthfully as possible precedes the study of instrument design and adaptation. The two courses in Instrumental Measurements are designated I and 11, but are informally thought of as introductory and applied. I n the former, measurements on static systems are stressed. In the latter, time is introduced as a significant factor either in the form of measurements on reacting systems, or measurements on flowing materials. The required senior analytical courses are respectively concerned with Modern Organic Analysis and with Analysis of Materials. The former stresses chromatographic and spectroscopic techniques, and the strategy of their efficient use. The latter course will be able to draw retrospectively on the students' work term experiences to formulate an approach to the analysis of "things as they are" rather than of student unknowns. The senior elective, Instrumentation, offers an opportunity to learn something of the optimum operation of instruments in the light of their internal components, and hence to consider the selection of available instruments, their modification to a given task, and the designs of new instruments at an assemhlyof-modules level. The First Analytical Course
This course occurs in the 2A semester. The students have spent either one or two work terms in industry before coming to this course, and are going to spend two more work terms before taking Instrumental Measurcments 1. These constraints have a definite influence on the course, and do not make it an easy one to organize and operate. In the 1R 'semester, the students have performed some quantitative experiments under less than ideal conditions in thc freshman lab. To this introduction, a stint as an analytical tcchnician has often been added. The student frequently has performed numerous analytical operations to a modest level of accuracy, and has acquired working habits appropriate to that goal. I n some cases, his tcchuique can only be described as "quick and dirty." Some students have already spent their working days with pH meters and spectrophotometers, and return with employers' remarks that they should know how to use such devices. The keynote of the course is development of justified personal confidence in personal technique. A secolldary goal is familiarization with simple basic instruments such as the pH meter. This conforms to a general departmental philosophy of not isolating instrumental methods, and hopefully minimizes instrumeut damage while maximizing correct results in futurc work terms. The cooperative plan and the proposed ultimate industrial employment of the graduate both suggest the choice of a compendious reference work as a textbook, and we have chosen Vogel ( 4 ) This serves as lab manual and lecture text, though we do not hesitate to prescribe methods from other texts for particular experiments. These are left to the student to consult in the library. Copies of various undergraduate textbooks, and of Hillebrand (5) and Meites (6) are available in the lab officefor ready reference. Two lectures a week are allowed in the course, and 520
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these are used to discuss sampling, treatment of data, gravimetric and volumetric analysis, ion exchange and solvent extraction, and basics of the operation and principles of the instruments used in the lab. Little time is devoted to the listing of items found in neat lists in standard textbooks, or to the development of standard pieces of mathematical hookwork. The reasons for the items in lists are discussed. The shapes of titration curves are used as a basis for discussion of titration tactics-indicator selection, buffer region problems, etc.,-from a practical viewpoint of getting titers and making buffers rather than as an introduction to the physical chemistry of solutions. Correlating principles and visualizing techniques are stressed such as the use of master variable diagrams. Stress is laid on the compromises and optimizations which go into choosing procedures and conditions, and on the limits of applicability of methods. The students are encouraged to ask questions about lab practice, difficulties, etc., in the lectures as well as in the lab. One problems hour is held each week. The text for this is Bard (7). Each week, three or four problems from one chapter are assigned which are a t the level of competence expectcd. Simpler questions may be recommended for anyone who has difficulty with the assigned questions. Any difficult idcas related to the assigned work are outlined quickly. The following week, the students are asked to write a solution for one of the assigned problems. A time sufficient to do the question if it has been previously thought out or worked out is allowed, and the papers are collected for marking. After the new assignment has been made, the rest of the hour is spent in discussing difficulties with the old assignment. Helps are subsequently posted for each question. These may range from a brief outline of key equations to a full solution with discussion. The laboratory is the heart of the course, and is assigned nine hours a week in three 3-hr classes, or a total of about 110 hrs. Each student is issued a substantial kit, and assigned to a separate locker. Students are free to draw extra equipment from the storeroom as they wish, and with certain exceptions may retain it for the scmester. Class A volumetric ware is issued, but students are required to check the calibration. (A 25-ml buret body which accidentally had 50-ml markings applied is kept as a horrible example!) A Wang 320 electronic calculator is available in the lab for immediate completion of calculations. The experiments are divided into four groups. Part A experiments are done by all students, and only these experiments are done during the first three weeks of the lab. Close attention is paid to developing good personal techniques in the use of washbottle, stirring rod, etc., and in transferring material quantitatively, titrating, and weighing. Part B experiments are assigned so adjacent students perform similar but different procedures. They are encouraged to compare notes on their work. I n Part C, several dcterminat'ions are performed on the same sample. Each student carries out one such group of analyses. Part D experiments are assigned at the discretion of the senior demonstrator to students who complete the other parts, or who show a weakness with respect to some area of technique. All experimcnts rcquire the reporting of
Organization of Analytical Experiments Part A (do all of) Water in a salt hydrate Grmimetric chloride Mohr titration (same chloride 8amDle) Ion exchange f& total cation Colorimetric Mn and Cr in steel Pwt R (do one from each group as assigned) 1. Volumetric unknown acid Volumetric unknown base 2. EDTA titration of magnesium (Erio T) EDTA titration of zinc (Xylenol Orange) 3. Titration of iron with cerate a t platinum electrode Titration of dibasio weak acid st glass electrode 4. Coulometric bromination of an oxinate Coulometric titration of As with iodine A
,
6. Analysis of mixture (HCO?-/Coax-) Analysis of mixture (H%POd-/HP042-) -
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results for unknowns. The table lists the experiments available. The laboratory is staffed by a senior demonstrator who is a full-time member of the staff and who is responsible for the management of all classes using the analytical facilities. Graduate student assistants are assigned to demonstrate in the usual way. The faculty member in charge of the course can thus spend time in the lab observing student work and discussing it without having to attend to details of housekeeping and management. A s s i g n m e n t of G r a d e s
Laborato~y marks are assigned for results on unknowns and for lab notebooks. At the end of each year, marking scales for unknowns are adjusted on the basis of accnmulated experience, and reported results are analyzed for signs of possible drift in any of the samples. Lab records are marked in the lab on a time-interval basis of two to three weeks. The demonstrator leafs through the notebook, asks a few questions to test the student's comprehension of what he has written, and then offers advice and assistance on the form of the noteboolc record and the work covered. The process takes about 15 min on the average. A one-hour midterm test on the entire course content to that time, and a 3-hr final examination are held. The orientation of the examination is shown by the question quoted below You are in charge of analytical work for a water softener company. A customer complains that water from his deionizing unit is of poor quality. The unit is reg-enersted regularly using hydrv chloric acid and sodium hydroxide. (a) What tests would you use to distinguish inadequate washing after regeneration from breakthrough of hardness salts (i.e., failure to deionize the water)? (b) What experiments would you order to determine total ionic content of the water? Explain how these work, giving suitable equations. (c) Write lab instructions far a technician who is to perform experiments to determine the amount of breakthrough of hardness salts. State what is to be determined and how to do it. (dl What ion would you determine to estimate the extent of
Par1 C (do one m o w as assigned) 1. Analyses oi tap water Total hardness (Cdmagite) Calcium (Hydroxy Naphthol Blue) Sulfate (chloranilatei Iron (0-ihenanthroli'ne) 2. Analysii of brass Gravimetric tin Eleatrodeoosition of lead ~lectrod&ositionof comer 3. Analysis of metal ion m h u r e Separation by ion exchange chromatography Colorimetric nickel Colorimetric cobalt Colorimetric CoPDer Part D (do as assignkd) 1. Titrimetry-Iran with dichramate Antimony with iodine Comer with thiosulfste 2. Gravimetry-Sdiate with barium Iron with hexrtmethylenetetramine
inadequate washing after regeneration? Propose a quick method involving little or no standardization. (e) The customer has sent pH and conductivity readings on water entering and leaving the deionizer. Show how you can interpret this information to help answer the shove questions.
The emphasis on obtaining a meaningful end result from analytical procedures and on intelligently directing the work of technicians should be noted. The final grade is made up of 40% for the laboratory, the same for the final examination, and 20y0 for problems and mid-term test. A university rule reauires thatthe final paper aswell as the final gradk be over>0%, and a student who has "signally neglected" his laboratory work may not write the examination. Summary
A new undergraduate program reflecting the demand for analytical training of contemporary relevance has been set up. The first analytical course in this program has been designed to lay a basis of good technique through a series of classical and simple instrumental determinations. As students become adjusted to the aims and philosophy of the course, their response is favorable. The equipment tends to be used hard but with proper care and respect. We are anticipating a rising enrollment in the program and a steady demand for its graduates. Further details about the analytical chemistry aspects of the program will be supplied upon request by t,he author. Literature Cited (1) (2) (3) (4)
LAITINEN, H. A., Anal. Chem., 40,265 (1968). Anon., Chem. d Eng. News, 45, 49 (Dec. 4, 1967).
KARGER, B. L.,Anal. Chem., 40, 123A (1968).
VOGEL,A. I., "Textbook of Quantitat.ive Inorganic Analysis" (3rd. Ed.), Longmans, Green & Co., London, 1961. ( 5 ) HILLEBRAND, W. F., LUNDELL, G. E . F., BRIGHT, H. A,, AND HOFFMAN, J. I., "Applied Inorganic Analysis" (2nd. ed.), John Wiley & Sons, New York, 1953. L., "Handbook of Analytical Chemistry," McGr~w(6) MEITES, Hill Book Co.. New York. -~ ~ - z -1963. - -(7) BARD.A. J., "Chemical Equilibrium," Harper & R o w Publishers, New York, 1966. ~
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