Introduction This experiment was necessary to study the reaction of food coloring with bleach. However, the principles on which the experiment was based can be applied to any other reactions. The main purpose of this test was to determine the reaction rate of two substances. The rate of a chemical reaction is the quantity of chemical that is reacted or generated for a given time interval (“Rate and Order Reactions”). The rate law demonstrates how the rate correlates with the concentrations of the components of the reaction. It is possible to note that “the power of the concentration in the rate law expression is called the order with respect to the reactant or catalyst” (“Rate and Order Reactions”). There are zero-order, first-order, and second-order reactions. There are several aspects of chemical reaction rates that are necessary for the understanding of the results of the experiment. The first important characteristic is absorbance. It demonstrates the amount of light absorbed by a given sample. It is also called optical density, extinction, or decadic absorbance (Helmenstine). This characteristic can be measured by means of a spectrophotometer. This device allows collecting necessary data in order to conduct quantitative analysis. A spectrophotometer calculates absorbance by measuring the quantity of light that goes through a given sample. The absorbance will be zero if all light passes through (Helmenstine). However, if the light does not pass through a sample at all, the absorbance is absolute. In order to calculate it, the Beer-Lambert law is applied. Another important aspect is the correlation between concentration and time. However, as absorbance is directly proportional to concentration, it was used to determine this correlation. Also, the collected data allowed determining the order of the reaction with respect to a given substance. The results of the calculations and graphs helped to demonstrate that it was the first-order reaction. The hypothesis of this work is that the reaction between the given substances is a first-order reaction. Procedure The stock solution that was prepared for this experiment contained six drops of the blue dye and distilled water. A 400ml beaker was used to mix the substances. The next step was to measure the absorbance of the stock solution. In order to do it, the stock solution was poured into the test tube. Then, it was put in the spectrophotometer. The wavelength was set from 700nm to 400nm, reducing 20nm each time. After the data was collected, the maximum wavelength at which the absorbance was the highest was determined. The next part of the experiment was to determine the right proportion of Clorox and blue dye solution to do the rate study. 1 mL of Clorox was mixed with different amounts of the blue stock solution using a graduated cylinder. The first proportion was 1 mL of Clorox and 10 mL of the blue dye solution. After mixing two substances, the discoloration time was measured. This pattern was repeated several times with different amounts of the blue dye. This experiment was completed when the discoloration time was about fifteen minutes. The final part was to make absorbance versus time measurements. The Spectronic 20 was blanked with water. Then, the blue dye and Clorox were mixed together and transferred into the cuvette to record the absorbance every minute. Results The results are presented in the two graphs attached to this report. Figure 1 demonstrates the correlation between the absorbance and wavelength. The highest absorbance wa