Letters to the editor - ACS Publications - American Chemical Society

Letters to the editor. George Kapp. J. Chem. Educ. , 1956, 33 (8), p 414. DOI: 10.1021/ed033p414. Publication Date: August 1956 ...
0 downloads 0 Views 389KB Size
JOURNAL OF CHEMICAL EDUCATION

Collect three 6-05, bottles of moist chlorine, generated in the usual manner by oxidation of hydrochloric acid by manganese dioxide. Obtain three rubber stoppers to fit these bottles and slit the stoppers on their lower ends (smaller area) along their diameter to a depth of I/, inch. Wedge a piece of the dry dyed fabric into each of these stoppers. Add anhydrous calcium chloride granules to one of the bottles to a depth of '/, inch and, stoppering it with a fourth stopper, shake the mixture thoroughly for about a minute. Wet one of the pieces of cloth, and insert the stopper bearing it into one of the bottles of moist chlorine. T o the Editor: The other two stoppers are inserted into the remaining All general chemistry t,extbooks state that chlorine bottles. Almost immediately the wet cloth becomes bleached acts as a bleaching agent when the material to be bleached is wet or moist but does nqt so function when and within five minutes the cloth inserted in the other bottle of moist chlorine is bleached. The cloth exposed t,he material is dry. In recent years we have not been well satisfied with to the dry chlorine gas in the bottle containing calcium the laboratory demonstration of this statement. Part chloride does not bleach during that period and, in of our difficultyappears to be in the choice of dyes, part fart, after a few days, still remains deeply colored. in our technique. The following method has been GEORGE KAPP devised to give excellent and speedy results: MILTONG. WOLR Dye a piece of cotton fabric with a one per cent JAMESMADISONHIGHSCMOOL solut,ion of either malachite green or methyl violet,. NEW YORK BROOKLYN,