Studies on the Pouer of Visual Discrimination of the Concentrations of Coloured Solutions

Abstract

In the present work, the power of visual discrimination of the concentrations of the several coloured aqueous solutions as the fundamental ability in the experiments and observations in science education is investigated. First, the fundamental conditons in the above discrimination are examined. Then, the relationship between the interval of concentration of the solution and the power of discrimination is clarifie. The order of the power of discrimination, from the viewpoint of its strongness, of the mentioned solutions is as follows : copper sulfate solution(blue), potassium bichromate solution (bitter orange), nickel nitrate solution (green), potassium chromate solution (yellow). In general, it can be confirmed that the above cases are almost in accord with Weber's Law in psychology.