Method for identifying sodium carbonate and sodium bicarbonate solution through chromotropic acid 2R-alcoholic solution

Abstract

The invention discloses a method for identifying sodium carbonate and sodium bicarbonate solution through chromotropic acid 2R-alcoholic solution. The method comprises the following steps: taking two small test tubes and respectively adding 2ml sodium carbonate and sodium bicarbonate solution; mixing chromotropic acid 2R with alcoholic solution with 20% of volume percent concentration of ethyl alcohol, thereby acquiring the red chromotropic acid 2R-alcoholic solution in which the volume ratio of chromotropic acid 2R to alcoholic solution is 0.0025%; respectively adding 1 drop of chromotropic acid 2R-alcoholic solution into the two small test tubes, wherein the red chromotropic acid 2R-alcoholic solution is faded to be colorless under the effect of the sodium carbonate solution, but the solution cannot be faded under the effect of the sodium bicarbonate solution and still is in original red color of the chromotropic acid 2R-alcoholic solution. According to the method provided by the invention, the problem of quickly identifying the sodium carbonate solution and the sodium bicarbonate solution which are both colorless and transparent can be effectively solved; better service can be supplied for production, life, scientific research and teaching; the device is simple; the operation is convenient; the drugs can be easily acquired; the phenomenon is obvious; the effect is good.

Description

technical field [0001] The invention belongs to the technical fields of medicine, chemical industry and chemistry, and in particular relates to a method for identifying sodium carbonate and sodium bicarbonate solutions with a chromotropic acid 2R-alcohol solution. Background technique [0002] There are two kinds of carbonates: normal salt and acid salt. Generally, normal salt is insoluble in water, and acid salt is easily soluble in water. It is used to explain the formation principle of natural landscapes of karst caves, stalactites and stalagmites. Affected by the explanation of this principle, people naturally think of using calcium chloride solution to identify sodium carbonate and sodium bicarbonate solution. In fact, this method is not feasible, because even a very dilute sodium bicarbonate solution with a concentration of 0.01 mol / L is mixed with a calcium chloride solution of 0.01 mol / L, and there is turbidity. See also: ① Liu Di, Li Datang. CaCl cannot be used 2 ...

AI Technical Summary

Problems solved by technology

Obviously, although the dissociated carbonate ions of sodium bicarbonate in aqueous solution are few, they are enough to produce turbidity or even precipitation with calcium ions. Practice has proved that it is impossible to distinguish sodium carbonate and sodium bicarbonate solutions with the prior art