The rate of a photochemical reaction depends on the absorption of light by the reactants, which leads to the formation of excited states that can undergo chemical reactions. The effect of temperature on the rate of a photochemical reaction is generally less significant compared to thermal reactions, as photochemical reactions are primarily driven by light absorption rather than thermal energy. However, temperature can still play a role in the reaction rate, particularly in the subsequent steps after the initial light absorption.As the temperature increases, the rate of a photochemical reaction can be affected in the following ways:1. The increase in temperature can lead to a higher population of molecules in higher energy states, which can increase the probability of light absorption and the formation of excited states.2. The increase in temperature can also affect the rate constants of the subsequent steps in the reaction, such as the decay of excited states, the formation of intermediates, and the overall reaction rate.To determine the activation energy Ea and pre-exponential factor A for a specific photochemical reaction, the Arrhenius equation can be used:k = A * exp -Ea / RT where k is the rate constant, R is the gas constant, and T is the temperature in Kelvin. By measuring the rate constants at different temperatures, a plot of ln k vs. 1/T can be constructed. The slope of this plot will be equal to -Ea/R, and the intercept will correspond to ln A . From these values, the activation energy and pre-exponential factor can be calculated.It is important to note that the activation energy and pre-exponential factor for a photochemical reaction may not have the same significance as in thermal reactions, as the reaction mechanism and rate-determining steps can be different. Nonetheless, these parameters can still provide useful information about the temperature dependence of the reaction rate.