To the Editor: I see your contributor from Illinois State Teachers College is horrified that a "practice teacher" thought he could make copper sulfate from concentrated sulfuric acid and copper. May I point out the following sequence: heating copper in concentrated acid, get: Cu
+ H8Oa
-+
CuO
+mZ +HX
(1)
Then with more acid:
On cooling, then add water, cautiously: CuSO, + 5H10 -r CuSO1tiH1O -
(3)
So the trouble with the "practice teacher" was that he did not jully recall what he had read! The overlined substances may be gas or vapor, underlined are solids. A little of the water product of (1) if ret,ained by the excess acid might promote reaction ,A,
I thoroughly agree with the general tenor of the article. But most teachen cannot afford A. C. S. membership, and too few articles in Industrial and Engineering Chemistrv ever t,ouch on their immediate
