Illustrating the laws of chemistry without chemicals

Illustrating the Laws of Chemistry without Chemicals We have found considerable favorable student interest in experiments designed to stress by analom the observations which led to an understanding of the Ism of chemical combination. We do IKLI very early in the introductory chemistry wuGe by hav~ngsnrdents weigh rtggregatcs of such objecra RJ pius, staples, or gummed ring reinforcements. Students obtain the weirht of a constant uwnber (snv 2011 of such small obiem with hinh orerisior~. Com~arironof such ueixhta can be made by &&inithe weight of some c o l l e c t i o ~ f ~ b j e c e.g., t s , thiring reinforcemen&, a value of unity on an 0.m.u. (object mass unit) scale. Thex comparisons lead to value for other articles exactly analogous to the atomic weights assigned to elements in the early nineteenth

--.."-.,.

-nt.,,~~

Various other principles of stoichiometry can be illustrated by appropriately designed directions for student "experiments!' These include the interdependence of atomic weight value and proportions also can be the formula for a binary comaound. The l a m of equivalent and multiple . . . demonstrated by analogy. . Interested readers m y obtain copies of the detailed instructions supplied to students by requesting them from the undersigned. RUTGERS UNIVERSITY NEWLRK, NEWJERSEY07102

334

/

Journal of ~hemimlEdumfion

JAMES M. SCHLEGEL ANNACHIN