What law relates light absorbance to the amount of reagent in the sample?

The Beer-Lambert Law, also known as Beer's Law, specifically describes the relationship between the absorbance of light by a solution and the concentration of a solute (in this case, the reagent in the sample). It states that absorbance is directly proportional to the concentration of the absorbing species in the solution and the path length of the light through the solution. In formula form, it can be expressed as A = εlc, where A is the absorbance, ε is the molar absorptivity, l is the path length, and c is the concentration.

This law is fundamental in analytical chemistry and is widely used in laboratory settings to quantify the amount of a particular substance in a sample based on how much light is absorbed at a specific wavelength. The significance of this relationship is crucial for various applications, such as determining the concentration of pollutants in drinking water or measuring the levels of specific chemicals in a solution.

In contrast, other laws listed do not relate absorbance to the concentration of a reagent. Henry's Law deals with the solubility of gases in liquids, Dalton's Law pertains to the behaviors of gas mixtures, and Charles's Law relates to the volume and temperature of gases. Thus, the Beer-Lambert Law