In colorimetric analysis, what does a darker color indicate?

In colorimetric analysis, the principle relies on the relationship between color intensity and concentration of a particular substance in a solution. When the color of a solution becomes darker, it typically signifies a higher concentration of the specific analyte being measured.

In this context, chlorine is often analyzed using colorimetric methods, where the intensity of the resulting color is directly proportionate to the amount of chlorine present in the water sample. If the sample turns a darker shade, it indicates that there is a greater concentration of chlorine in that sample. This is important for monitoring water quality, where adequate chlorine levels are necessary for effective disinfection and ensuring safe drinking water.

While other options mention various substances (like dissolved oxygen, minerals, and ions), they do not relate to the common colorimetric methods used to detect chlorine. Thus, the darker color serves as a key indicator of chlorine concentration specifically in this analytical method.