How does temperature affect reaction rates?

Higher temperatures increase molecular velocities, which enhances the likelihood of effective collisions between reactant particles. As temperature rises, the kinetic energy of the molecules increases, causing them to move more rapidly. This increased movement means that particles collide more frequently and with greater energy. In chemical reactions, not only does the frequency of collisions matter, but the energy with which the particles collide is also crucial.

For a chemical reaction to occur, the colliding molecules must have a certain amount of energy, known as the activation energy. When temperature rises, a larger proportion of the colliding molecules possess enough energy to overcome this activation barrier, resulting in a greater number of successful reactions. This is why, with higher temperatures, the rate of reaction typically increases. In summary, the increase in molecular velocities at elevated temperatures leads to a higher rate of effective collisions, making this the correct choice.