TWO SIMPLE AND CONVENIENT GAS GENERATORS

C. E. LINEBARGER
1901 School Science and Mathematics  
work until you get two results that correspond with each other. Arrange the results as in the preceding experiment. Then repeat this work, using phenolphthalein in the place of methyl orange. The hydrochloric acid must be added very cautiously, keeping the solution well stirred so as to avoid effervescence. Arrange results as before. Are the amounts of acid that react with a given quantity of sodium carbonate -the same in the two cases ? If not, is there any simple ratio between them? This
more » ... iment has immediately followed one illustrating the law of definite proportions, by the titration of acid with alkali, using phenolphthalein as an indica tor so that the directions for manipulation are not as full as would otherwise be needful. The stock solutions are approximately normal. Students have obtained better results by working with solutions of this strength and diluting in the beaker than by using more dilute solutions directly. A variation of the above experiment is to dissolve an indefinite amount of sodium carbonate in the beaker, add both indicators and t'itrate with acid. This method does not give as exact results in the hands of students, but, on the other hand, it is simpler, and the principle involved is more easily grasped.
doi:10.1111/j.1949-8594.1901.tb00028.x fatcat:n4c5njxu4jgdbn5ulbf7bqytra