was published with the idea of provoking criticisms, this letter is humbly submitted. RALPHE. SILKER TEAC~ERS COLLEGE NeBmsKn STATE CEIADRON, NEBRASKA
CHEMICAL EQUATIONS To the Editor: DEARSIR: I wish to submit the following criticism of the article "On the Writing of Chemical Equations" which appeared in the JOURNAL OF CHEMICAL EDUCATION, 15,75 (1938). It is my opinion that Mr. Jacobs is correct in stating that beginning students find equations ~ r a d i c a l l or ~, entirely, meaningless when written in the ''old way." However, if one discusses atomic structure and ion formation before the use of formulas and equations are introduced, the various concepts have a vexy real meaning to them. I was greatly surprised to note the manner in which the author proposed to remedy the situation. To begin with, may I ask whether one will find many teachers writing the equation for a neutralization reaction, or others involving electrolytes, without the use of the ions which are involved? Too, if one should chose to use molecular formulas would it not be far wiser to use bold type for the portion of each substance which undergoes change?* Thus, to use the illustration of the reaction between sodium hydroxide and hydrochloric acid which the author cited, and if one feels he must use molecular formulas and is to employ the proposed scheme, I think it would be much better to indicate that the hydrogen atom and the hydroxide group react to form water, since this represents what does take place. A minor point which has always nettled me, Personally, is the use of equality signs in equation writing. This practice may cause a COmmon misconception in the mind of the student and should be avoided. Another surprise which was was the naming 1, 2 , 3-trichloro~ro~ane as glycexyl trichlorh~drin. The name is a misnomer, and while it may have been in good usage sometime ago, I have failed to find it mentioned as such in five current texts. The reference to the hydrolysis of the above compound being written by use of molecular formulas is beyond me. Where will one find a teacher of organic chemistry who does not use structural or semistructural formulas? Assuring you that I think the editors of the JOURNAL OR C ~ R M I C A LEDUCATION are doing an excellent piece of work and with the belief that the article in question
"PREPARATION OF CONSTANTBOILING HYDROBROMIC ACID"
To the Editor: DEARSIR: I always like your ~h~ paper on H B in ~ the A P ~ ~1937, I , issue of "JCE," page 189, has aroused me to as urged me to write you. iqy feelings are the write Dr. Gordon, for which see "JCE" May, 1930. we au know that iodine and bromine are the raw beginnings of all their compounds. Why, therefore, Mr. Editor, give us a paper startingwith expensive KBr, pure H ~ S Oand ~ also mentioning red phosphorus, and adding s n cto~give a chlorine impurity? ~ , dthat $10.00 I offered D ~ &,.don . has noteven made a ripple of a query. Well, all the students of 1930, I hope, have jobs, and you write for a new crowd; perhaps a bright student in the sticks can still win it. what do you say? students seem in a vacuum, becoming aware only they enter the outer world of pressure of costs. hi^ paper on HB,. is a case in point. -I&EC" quotes Br a t 306, HBr 10% a t 186. So 100% HBr on this basis is six times the HBr price or nine times the ITBr a t 316 and twelve or more the K B price ~ using H ~ S Oetc., ~ , and, be wasted. ( ~ ~ of course, the KHSO~ much higher.) 1, my paper which DI. ~~~d~~ kindly published (p.) I gave the method usedsimplicity itself-fully in a paper read before the British Pharmaceutical Conference a t Dublin thirty-seven years ago, I think, since when the H2S, SO2 processes have been abandoned. I humbly ask you as an educational authority why my process has not just naturally seeped into the textbooks. Your authors. Heisig and Amdur, mention the literature, but what I should like to know and alter is, how their pure minds never once raised the question, "How does the ma,,ufacturer?H iyo, they mention red phos. phorous (40#, case lots), but omit the fumes. he reagent firms are keen competitors, as your advertisements prove. They must make a profit. Their products are made with the cheapest raw materials, the least time, labor, and plant set-up, for the "best" product must be best from all points. But the chief point is the cost, settingthe price. Granted that laboratories buy many products obt i n e d only by mass production, still, many inorganics used in first-year courses could be made by the advanced * Editor's Note.-It was not possible in all cases to reproduce students to their very great advantage, in thought and exactly the type differentiations employed in Mr. Jacobs' original training and at a saving in school money which is almanuscript. In this instance conventional boldface type was ways below staff requirements. used in place of a font not available to us
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