as well. All materials. includine experimental write-ups suitable for distribution' to studeks,'can be ordered frbm the Project SERAPHIM Catalog. .
Project SFKAPHIM is supported by the National Science Foundation, Grants No. SPE-LC!-6318: and SI'K-R1-00051. Views expressed in this article are not necessarily those of the National Science Foundation.
Exploring Chemistry by Computer: KC? Discoverer Aw Feng and John W. Moore
Eastern Michigan University Ypsilantl, MI 48197
b.
Figure 10. Space-filling diagrams generated on iBM PC by MOLDOT. (a) [2.2]Metacyciophane.wiihout hydrogens, based on ref. 14. (b) 2,ll-Diihia[3,3]metacyciophane,without hydrogens, based on ref. 15. from purple back to orange in the colorimeter, where the onlv light is provided by a meen LED. Without the higher speed data c&ection afforded by the computer it would be impossible to obtain the requisite number of data points, even a t low temperatures. ~ L c a u s the e reaction is rapid and can be reproduced simply by reirradiating the sample, it is ~ossibleto studv the effects of temoerature and catalvsts on the reaction and easily. ~ a i experimental y r i n s can be carried out and analvzed in a sinele class period. The other six experiments are shorter and are especially suitable for hieh school chemistrv laboratories. Beer's Law with the ~lock&onicI is a simplecalibration of the colorimeter using Cr3+ion solutions. Kinetic Study of theDecomposition of Thiosulfate in Acid involves precipitation of sulfur by acidification of thiosulfate and is based on a standard kinetics experiment. Kinetic Study of the Reaction of Ferric Ion with Iodide Ion measures the absorbance due to 1 2 produced when iron(II1) . . oxidized iodide. Cooline" and Heatine Curve provides for continuous monitoring of the temperature of lanric acid as i t is cooled and then reheated through its melting point; two thermistors are used, one for thelauric acid and one for the thermal surroundings. Simple Heat of Reaction is a computerized version of the standard experiment where stoichiometric amounts of acid and base are mixed but designed so that up to four students can use the same computer a t the same time. Freezing Point Depression of a Mixture involves a study of the freezing point of cyclohexanol containing different concentrations of benzoic acid. Currentlv software and adaoter boxes are available for ~ ~microApple 11e/i1+, Apple IIc, and d o m m o d o r e - 6 4 1 64 computers; they are being developed for IBM PC and PCjr
How would you like t o have a computer-searchable handbook of chemical facts for all the elements? KC? Discoverer is a program that provides students with just such a function. I t is based on the suaaestion made at the Proiect SERAPHIM Powwow I meet&; (35) that it might be possible to devise a computer program that would allow students to explore physical and chemical properties of the elements. An outline for such a program was provided in reference (35). We report here version 2.0 of KC? Discoverer, which includes most of the features suggested by Powwow I participants. KC? Discoverer consists of a database and several programs that provide quick and easy ways to explore, manipulate, and display graphically the data. For each of the elements 46 ~hvsicaland chemical orooerties are stored. (Fieure I1 shows the screen .display fbr hydrogen indicating which properties are included.) The program helps students (or facht;) to search for all elements thBt have particular property, to sort the elements in order according to a certain property, to graph any property against any other on a set of Cartraian axes, or to select elements according to the period-
a
DISCOVERED: 1766 mum cnsI(os: 10.5 ABUNO CRUST: No data. COST: 0.2 $ / k g ELEC.CONDUCT: Wo data. HARDNESS: No d a t a . TOXICITY: lor CObmON OX. NOS:
NANE: *TO)IIC NO: s m m :
m n m c w: DENSITY: ETATE(S.I.B); MELTING FT: BOILING PT: HT OF PUSION: HT OF YAP: THER CONDUCT: COLOR: RX r U R : RY u WATER: RX r ACID:
.
N W : ATOIIIC NO: S W L : NO. ISOTOPE:
colorlelP
burns explosival) none none
Hydrogen 1
H
3
1st 1 0 N . H G :
,318.0
2nd ION.EIIC: 3rd ION.ENG: bth ION.ENG: ELBC.APPIN: POLUIIUBILITY: ATMIIC VOL: COV.R*DIUS: IONIC RADII: 2
No data. No d a t a .
1 : (it):
(2,): (3+)2
kJlnol
No data.
73.0 kllmol 0.4 1 ' A 14.1 cm"31md 32.0 om
ELECTRONEC: 2.2 PORrmU OF HYORIDE: H2 P O W OF OXIDE: HZO,H202 QORINU OF CHLORIDE: MCI NO. ALLOTROPE: No data. STRUCWRE: No date.
NO *at.. No data. data. NO data. No data. NO
Figure 11. Screen displays t o m KC? Discoverer. (a) Macroscopic properties of hydrogen (b)microscopic proflier of hydrogen displayed on a separate screen.
Volume 63 Number 4
Agril 1986
327
ic group and then graph or sort their properties. Results of on a periodic table so that relasearches can he dis~layed . tiunihil~iamong elrrnents can he seen; for example, Figure I2show; the result d a s e n r c h fur all elements that are gases at room temperature and normal pressure. The graphing capabilities of KC? Discoverer are especially helpful (and often addictive to chemists). Graphs can he constructed using any numeric property on either axis, or any pair of properties can he combined by addition, suhtraction, multiplication, or division and the result plotted on the y axis. Figure 13 shows the result of plotting the difference between second and first ionization energy on the y axis versus atomic number on the x axis. Note that a symbol is printed for each element whose y-axis value is a maximum, numeric values of the x and y coordinates can he displayed for any element, and any portion of the graph can be enlarged so that it is easy to see details. Figure 14 shows the result of selecting elements by periodic group and plotting their melting points; selecting several groups superimposes their graphs and can be very effective for detecting anomalies such as the often large differences between second- and third-row elements. We have used KC? Discoverer together with simple prohlems as assignments t o introductory chemistry students. For example, students can easily find answers to questions like: Which elements would be liquids within the range of temperatures on Jupiter or another planet? Which elements might be used as a replacement for copper in electric wiring? Which elements will form diatomic hydrides that are nearly nonpolar? The program is easy to learn to use because menus are available for almost all choices. I t is quick-finding all elements that are gases, for example, requires only 30 s or so, as does producing the graphs shown in Figures 13and 14. Program speed is almost entirely limited by disk accesses, and storing program and data in a RAMdisk reduces the times quoted above t o less than 5 s, exclusive of the necessary keystrokes to tell the program what to do. The full power and utility of KC? Discoverer cannot he described easilv on the printed ~aee-as with many eood . .. cumputtr uppl~alionsfhisprogram iseauier toevalua~te~first hatid than to describe, hecause it enables you t o do things you would otherwise not even try. Rather than provide fuither description we invite interested readers to try the program, which is listed in the Project SERAPHIM Catalog (January 1986) as IB 299. KC? Discoverer requires an IBM PC with 128K memory, one disk drive, and DOS 2.0 or higher; if 448K or more of memory and RAMdisk software are available, performance can he greatly improved by storing program and data in memory instead of on disk. ~
Oltwnts that kve bm found in state bur 'C' ualut. (CR) Figure 12. Periodic table generated by KC? Discoverer following a search fw all elements mat are gases at rmm temperature and normal pressure.
X-axis Y-axis Cr 24,P 939.3 Sy
Ih 25.8 791.2
R 26,8 801,2 CP 27,01307.5 28.0 1814.6 Cu 29.0 1218.8 Ni
e.eJ 0.0
12
23
Continue or Maw ?
35
17
59
79
atomic no
I2
Figure 13. Graph of difference between sound and first versus atomic number generated by KC? Discoverer.
ionization energies
SY X-axis Y-axis
1.... 13.9 Li 453.5 B 378.9 K 336.6 Rb 311.9 Cs 301.4 Fr 7 380.8 -.--pup 2---& 2 1556.0 IR 3 923.8 Ca 4 1123.0 SF 5 1843.9 Ba 6 983.0 Ra 7 1233.0 -.-.9To
H
I 2 3 4 I 6
Figure 14. Graph d melting point versus period number for groups 1. 2. 6, and 10 generated by KC? Discoverer. 528
Journal of Chemical Education
Acknowledgment Project SERAPHIM is supported by the National Science Foundation, Grants No. SPE-82-63187 and SPE-84-00351. Views expressed in this article are not necessarily those of the National Science Foundation. Literature Cited I11 Sparrow, G.J. ChemEduc. 1985,62 139. I21 Roseher& R. M. J . Chem. Educ. 1985.62.140. (3) Whitten, W. K.: Gailey, K. D."Expriment, in General ChmGstry"; Ssundcrs: Philadelphia, 1984; p 141. (41 "Acculab infrared Speetromelors Operating Instructions": Beekman Instruments: Pullerton. CA. 1978. (5) Mebbott,G.M. J. Chom.Edue. 1983.60.697. (6) Kinsin~er,P.T.;Heinemsn, W. R. J. Chem. Edue. 1983.60.702. (7) VanBenschoten,J.J.:Lewia,J.Y.:H.ineman. W.R.:Roaten,D.A.;Kissinger,P.T. J. Chem. Educ. 1983.60.772. 181 Baldwin, R. P.; Ravichandran, K.; Johnson, R. K. J. Cham. Educ. 198481,820.
(91 Diefenderfer,A.U."Principl~sdEl~efronictnstrumenfation";Saunden:Philsdelpie. 1972; p 552. (10) E8aki.T. A n d Chim. Aelo 1981,133,657. (11) Msr,N.L. J. Med.Sysiema 1982.6.485. (12) North, A.C.T. C h e m l n d . 1982.221. (131 Richards, W. G.;Mangold, L. Endsnuovr 1983.7.2. (11) Brawn.C.J. J. Chrm. Sac. 1953.3278. (151 Anker, W.: Bushnell, G. W.;Mileheil,R. H. Con. J. Chsm. 1979,57,3080. 1161 Egan, J.T.; MacElroy, R. D. Computer Pmgroms B i o m d 1980,12,203. 117) C1ark.D. D.;Schuster.S.M. Comp. Chrm.,1980.4,75.
