A VARIANT METHOD OF SOLVING CHEMICAL PROBLEMS In the March issue of the JOURNAL, page 440, I note with interest an a r t i c l t U AVariant Method for Solving Chemical Problemsn-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 t o react with the 40 grams of zinc.
65 - = 40
-
72 X.'
2880 X9 = -or 4430 g. 65
PROPOSED METHOD Steps 1, 2, 3 are the same, then the following:
Gram wt. given X
M. W, unknown M. W. known
or
2 80 40 g. X - or - = 1.23 g. 65 65
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 EVENING TECHNICAL HIGHSCHOOL, SCRANTON, PENNA. Australians Make Paper from Eucalyptus Wood. Australia's paper requirements may eventually be met by the product of native paper mills, although a t present all paper used in the commonwealth is imported. Eucalyptus fiber has been successfully made into paper on an experimental scale by two Australian scientists. Hitherto, attempts a t utilizing hardwoods like eucalyptus have not been successful, because the mechanical methods of producing pulp will not work with hardwoods, and the standard alkali processes for producing chemical pulp have resulted in paper that is too bulky, soft, and "short" when tried with eucalyptus. However, a modification of one of the alkali processes has been worked out by the two Australians which gives a paper of satisfactory finish and strength.-Science Service
