What is the role of a catalyst in chemical reactions?

A catalyst plays a crucial role in chemical reactions by increasing the reaction rate without being consumed in the process. This is accomplished through its ability to lower the activation energy required for the reaction to proceed. By lowering the activation energy, more reactant molecules have enough energy to overcome the energy barrier, which results in a higher frequency of effective collisions between molecules.

This enhanced interaction leads to a quicker formation of products, facilitating the reaction without altering the overall equilibrium or the products produced. Importantly, since the catalyst is not consumed during the reaction, it can be used repeatedly, making it a vital component in many industrial and biological processes.

While other options touch on various aspects of chemistry, they do not accurately describe the function of a catalyst. The catalyst does not become consumed (as suggested by the first option), does not alter the mass of the reactants (as mentioned in the second), and it does not change the products formed (contrary to the fourth option)—the products remain the same, but the pathway and rate to reach them are modified by the presence of the catalyst.