Final answer:
Heat enhances the rate of chemical reactions by increasing the kinetic energy and collision frequency of reactant particles, as well as the force of these collisions, which leads to a greater number of effective collisions that have enough energy to surpass the activation energy barrier.
Step-by-step explanation:
Heat plays a significant role in the speed of chemical reactions. When the temperature of a reaction is increased, there is an increase in the kinetic energy of the reactant particles, causing them to move more swiftly. This movement leads to a higher frequency of collisions between the reactant particles. Not all collisions result in a chemical reaction; only those with enough energy to overcome the activation energy barrier will successfully produce products. When heat is applied and the temperature rises, the force of the collisions intensifies, which means a higher number of these collisions will have sufficient energy to overcome the activation energy barrier, leading to an increase in the reaction rate. In practical terms, for many chemical processes, it is observed that reaction rates tend to double with every 10 °C rise in temperature.
Such an increase in temperature does not only increase the frequency of collisions but also the percentage of those collisions that are effective. Hence, heating up reactants often is a common method employed in laboratories and industries to accelerate slow reactions, exemplified by the use of burners, hot plates, and ovens. An example that illustrates the importance of temperature in everyday life is how food spoils quickly at warm temperatures but lasts longer when refrigerated, due to the slowdown in the reaction rates at lower temperatures.