The relationship between light intensity and the rate of photochemical reactions, such as the oxidation of iodide ions by hydrogen peroxide in the presence of UV light, can be described by the Bunsen-Roscoe law of photochemistry. This law states that the rate of a photochemical reaction is directly proportional to the intensity of the light source.In the specific reaction mentioned, iodide ions I are oxidized by hydrogen peroxide HO under UV light to form iodine I and water HO . The overall reaction can be represented as:2 I + HO + UV light I + 2 HOAs the intensity of the UV light increases, the rate of the photochemical reaction also increases. This is because a higher light intensity provides more photons, which can interact with the reactants and promote the reaction. Consequently, more iodide ions are oxidized, and the reaction rate increases.However, it is important to note that the relationship between light intensity and reaction rate may not be linear at very high light intensities, as other factors such as reactant concentrations, temperature, and the presence of catalysts or inhibitors can also influence the reaction rate.