Chemical reactions visualized for beginners - Journal of Chemical

CHEMICAL REACTIONS VISUALIZED FOR BEGINNERS* In beginning the study of chemistry the use of symbols in formulae and in the writing of equations to express chemical reactions is a part of

* Read before the Division of Chemical Education at the New Haven Meeting of the American Chemical Society.

the study that presents some considerable difficulty to the student. The symbols which we are accustomed to use are the letters of the alphabet, and these letters do not carry any idea of mass, or substance. These letters are the symbols each for a different sound. In the study of algebra, the letters have been used to represent abstract mathematical quantities, or magnitudes. They do not of themselves suggest mass, or substance. Now, in chemistry each symbol is to represent a perfectly definite mass, or weight, a very small particle of an element, called an atom. I t becomes

I

zh!1 I

I

I

I

I

i H lh M C L I I

I

I

The creases are made by folding: 1. Into halves, with symbols inside. 2. Into quarters, by folding back the outer free ends, showing the symbols.

necessary to teach the beginner to associate the idea of mass, or substance, with the letters as used in chemical formulae. We find that a letter drawn in prospective does convey very readily the idea of mass, or substance. In the accompanying plate burning as oxidation is illustrated; also,

in the lower half, one can readily visualize the displacement of hydrogen hy a metal from an acid. In this manner we present to the beginner such a topic as neutralization of an acid by a base on the ionic theory and it is simplicity itself. The mechanics of the reaction can be easily grasped by the beginner in a way that both interests and instructs at the same time. Many of the great generalizations of the science of chemistry become readily intelligible to the enthusiastic beginners.