How does temperature influence exothermic and endothermic reactions?

Temperature influences exothermic and endothermic reactions by affecting the rate at which these reactions occur.

In both exothermic and endothermic reactions, an increase in temperature typically increases the rate of the reaction. This is because temperature is a measure of the average kinetic energy of particles. When the temperature increases, the particles move faster and collide more frequently and with greater energy. These more frequent and energetic collisions increase the likelihood of successful reactions, thus increasing the rate of the reaction.

In an exothermic reaction, heat is released as a product. Examples of exothermic reactions include combustion reactions and many oxidation reactions. When the temperature is increased, the particles have more energy, and thus the reaction rate increases. However, according to Le Chatelier's principle, if a system at equilibrium is subjected to a change, the system will adjust itself to counteract that change. So, in an exothermic reaction, if the temperature is increased, the equilibrium will shift to favour the reverse reaction (which is endothermic) to absorb the extra heat.

On the other hand, in an endothermic reaction, heat is absorbed from the surroundings. Examples of endothermic reactions include photosynthesis and the process of dissolving some salts in water. When the temperature is increased, the particles gain more energy, and the reaction rate increases. According to Le Chatelier's principle, if the temperature is increased in an endothermic reaction, the equilibrium will shift to favour the forward reaction (which is endothermic) to absorb the extra heat.

In summary, while an increase in temperature generally increases the rate of both exothermic and endothermic reactions, the effect on the position of equilibrium can be different. For exothermic reactions, an increase in temperature can shift the equilibrium to favour the reverse reaction, while for endothermic reactions, an increase in temperature can shift the equilibrium to favour the forward reaction.