Information • Textbooks • Media • Resources edited by
JCE WebWare
William F. Coleman Wellesley College Wellesley, MA 02481
Abstracts of Recent Articles
W
Three articles, whose abstracts appear below, have been published as part of JCE WebWare, a feature that can be found Only@JCE Online. JCE WebWare articles include one or more Internet applications for teaching/learning chemistry. In particular, these applications involve some element of active learning on the part of the student. The goal is to make available tools that can be used not only in the classroom and laboratory, but also in the computer room and the student’s dorm room or home. Such tools may include Java applets, dynamic HTML (DHTML) pages, virtual reality (VRML), QuickTime and Flash movies, animated gifs, and applications that can be used over the Internet with helper programs such as Excel. All JCE WebWare applications run equally well on PCs and Macintoshes. These applications are at http://jchemed.chem.wisc.edu/ JCEWWW/Features/WebWare/index.html (from the JCE Online home page, click Features in the Only@JCE Online menu and then click the JCE WebWare link in the body of the page or in the right-hand menu). There are also several example “snippets” available to give you a flavor of the types of tools we expect this feature will provide to JCE readers.
An Excel Program to Study First-Order Kinetics
W
Ken Muranaka, K’s Garden Nishioji, Suite 401, Kasuga Hachijo Sagaru, Minami-ku, Kyoto 601-8312, Japan
Software to analyze and to simulate first-order kinetics data (ExpoDecay) has been developed using Microsoft Excel 97 with Visual Basic for Applications. Data can be analyzed by least-squares with and without weighting. The results can be assessed by Student’s t-test and ANOVA tables. Half-life and a 95% confidence interval for an observed value at time t are given also. For simulation, noise can be added by the constant-variance model and by the constant coefficient of variation model. Some Unusual Applications of the W “Error-bar” Feature in Excel Spreadsheets Kieran F. Lim, School of Biological and Chemical Sciences, Deakin University, Geelong Victoria 3217, Australia
W
P. Nikitas and C. Malliakas, Laboratory of Physical Chemistry, Aristotle University of Thessaloniki, 54006, Thessaloniki, Greece
The problem of the simultaneous smoothing and integration of data is examined using orthogonal polynomials and a simple approach for integration of the trial function is presented. This approach has the advantage that the procedure of integration does not introduce any error and that it can be used for integration of equally and non-equally spaced data. It is also shown that this technique of smoothing and integration can be easily performed on spreadsheets, such as those of Microsoft Excel 98 or 2000, within a moving data window or directly from a certain point to another one of the data set. For this purpose a new function has been written, named Integr(x, y, n, IDegree, xa, xb), which can be used for either smoothing or integration of data on spreadsheets of Microsoft Excel. From the arguments of this function x is a set of N x-values, y is the corresponding set of y-values, and n is the degree of the fitted polynomial. The function calculates the integral between the points xm and xm+1 when IDegree ≠ 0 and xa, xb are omitted. (In all cases, if N is the number of x points, m is equal to the integer part of the ratio N/2.) When values for xa, xb are included, then the function calculates the integral between these two points. If IDegree = 0, the function calculates the smoothed value at the point xm+1.
This paper demonstrates how the “error-bar” feature can be used to extend the utility of “worldware” spreadsheet packages in producing high-quality graphs for university teaching and learning, and for research. To further utilize the advantages of spreadsheets in university education, this paper seeks to overcome some of the earlier reservations about the lack of scientific plotting capabilities of spreadsheet applications. Specific examples of educational material in the areas of enzyme kinetics, vibrational spectroscopy, vibronic spectroscopy, and mass spectrometry are discussed. It is argued that, where practical, university educators should use “worldware” packages to prepare teaching aids, since these would better prepare their students for future employment. The use of software features for purposes that were not envisioned by the programmers has additional educational benefits in fostering flexibility and innovation. Other graphing packages can also use the “error-bar” feature in a manner similar to that described here for Excel. v'=24
Visible absorption spectrum of gaseous iodine showing the main vibronic sequence and hot bands.
v'=18
0.3
Absorbance
A Simple Technique for Simultaneous Smoothing and Integration of Data
Randall J. Wildman University of Wisconsin–Madison Madison, WI 53715
v"=0 v'=24
v'=19
v"=1
0.2
0.1
0.0 545
555
565
575
Wavelength / nm
JChemEd.chem.wisc.edu • Vol. 79 No. 1 January 2002 • Journal of Chemical Education
135
