A VARIANT METHOD OF SOLVING CHEMICAL PROBLEMS In the March issue of the JOURNAL, page 440, I note with interest an article-"A Variant Method for Solving Chemical Problemsv-the contents of which have always been of deep concern to me in teaching chemistry problems, involving weights, to high-school students. I believe I have a much simpler method which eliminates the step involving the direct proportion, a step which I find is confusing to many students. Taking an example and proceeding according to the usual chemistry text:
.
When 40 grams of zinc react with dilute hydrochloric acid. calculate ( 1.) the number of grams of hydrogen liberated, and (2) the number of grams of hydrochloric acid necessary to react with the 40 grams of zinc
PRoPosEo METHOD Steps 1, 2, 3 are the same, then the following:
Gram wt. given X M' W' unknown M. W. known
ir
2
40 g. X - or v 05
80 -
65
= 1.23 g
The simplicity of this method is apparent and the ease of solving these problems is evident as we keep in mind only that we multiply the gram weight given by the molecular weights of the unknown substance over the known substance. ERNESTE. WELLES EVENINO TECHNICAL HIGHSCUOOL, SCRANTON, PENNA.
