Laboratory jack: Apparatus for undergraduate laboratories

year, leaving room for 55 units (181/3 semester hours) of technical electives in the senior year. The needs of ... BS degree are quite different from ...
2 downloads 0 Views 990KB Size
The Revised Curriculum

Although the Valency and Structure course has had some impact on the teaching of all other chemistry courses following it, the beginning organic course and the senior inorganic course have felt the greatest influence. The organic course starts immediately with organic reactions and essentially no time need be devoted to structure and nomenclature. A complete discussion of each reaction, including stereochemical aspects, can now be given from the very beginning. As an example, a discussion of bromine addition to olefins during one of the early lectures could include addition to cyclohexene to give trans-1,2-dibromocyclohexane and addition to cis- and trans-2-butene to give dl- and meso-2,3-dibromobutane, respectively. The sequence of chemistry courses in the new curriculum is shown in Table 3. An important feature of the revised curriculum is the flexibility offered in the senior year. Nearly all of the required chemistry courses have been completed by the end of the junior Table 3.

Sequence of Chemistry Courses in the Revised Curriculum

Semester 1 2

3

4 5

6

7 8

Course

... ...

General Chemistry ... General Chemistry ... ... Vdeney and ... Structure ... Physical Chemistry Chemical Measi urements I Organic Chem- Physical Chemistry Chemical Measistry I I1 urements I1 Organic Chem Physical Chemistry ... istry I1 111 Quditat~ve ... Inorganic and Organic Nuclear Andvsis Chemistw ... Instmmenthl ... Analysis

A. W. Cordes

year, leaving room for 55 units (181/3semester hours) of technical electives in the senior year. The needs of the student planning to take a job after earning the BS degree are quite different from those of a student planning graduate work in chemistry. For the latter group two-semester basic graduate courses in the three areas, physical, organic, and inorganic-nuclear chemistry are available. Our better students commonly take one or t v o of these basic graduate courses during their senior year and one student has taken all three. The basic graduate course in inorganicnuclear chemistry can be substituted for the regular senior course. The jump to the graduate course is made easier for the undergraduate student by the background in modern inorganic chemistry gained from the Valency and Structure course. Conclusions

The Valency and Structure course has been enthusiastically received by the students. The level of student interest and participation in the courses in organic and physical chemistry which follow is now noticeably higher. The course has been a popular elective for sophomores from other departments who (usually by reason of advanced standing in one or more subjects) have sufficient flexibility in their course program. In each of the three years the course has been taught, it has influenced one or more outstanding students from other departments to become chemistry majors. The loss of capable chemistry majors during the sophomore year has stopped. Finally, the course provides the necessary foundation for a truly modern beginning organiccourse. The author gratefulIy acknowledges important contributions to the development of the Valency and Structure course by Professors Robert R. Holmes, Albert A. Caretto, and Walter A. Manch.

Laboratory Jack

University of Arkansas Fayetteville

Apparatus for undergraduate laboratories

Laboratory equipment jacks are extremely useful pieces of laboratory apparatus, yet the cost of the commercial models usually prohibits their widespread use. We have found that an inexpensive, lightweight automotive jack can easily be converted for laboratory use. A small scissors jack, rated a t 1-1.5 tons capacity, may be purchased for less than $5 from almost any store handling automobile accessories. The average jack of this size has a range of 4-14 in. New jacks are sometimes quite stiff and should be "exercised" and lubriEDITOR'S NOTE: Probably readers who have had the experience of similar demands on ingenuity to replace funds will be able to contribute to s. series of articles on this theme. We ~olieit only descriptions of instruments proved to be satisfactory by 40,641 (1963); 41,12 (1964). laboratory use. See THIS JOURNAL,

130

/

Journal of Chemical Education

cated until they work freely. Minor modifications are then required for use as a laboratory apparatus: the jack is not equipped with a means of lowering the unit with the screw, so a large washer held in place by a cotter key must he fmed in the position shown "" in the sketch to make this possible; a large, round handle such as thoseused on water valves must be soldered onto the shaft which normally accommodatesthe jack handle; and a platform of wood or metal must be bolted to the topof the jack.