Temperature was the variable that had the greatest influence on the copper oxide conversion yield, with a positive effect according to the Pareto chart (Figure ) and ANOVA (Table ). This means that high synthesis temperatures favor the conversion of copper oxide and may be related to various factors. According to Arrhenius's theory, the speed of a chemical reaction generally increases with increasing temperature . Therefore, high temperatures increase the average kinetic energy of molecules, and this increases the probability of collision, which will eventually favor the reaction rate and conversion of the desired product .