What is the role of catalysts in chemical reactions?

Catalysts play a critical role in chemical reactions by accelerating the reaction rate without being consumed in the process. This means that they can be used repeatedly, which is a key characteristic that distinguishes them from other substances that might alter the course of a reaction. By lowering the activation energy required for the reaction to proceed, catalysts increase the rate at which reactants are converted into products, allowing the reaction to reach equilibrium faster.

For example, in catalytic converters in automobiles, catalysts help convert harmful gases into less harmful emissions more efficiently. This showcases their importance in both industrial processes and environmental applications.

The other options do not accurately capture the true function of catalysts. They do not get consumed in the reaction, thus they are available to facilitate the reaction repeatedly. While some substances can slow down reaction rates, catalysts specifically work to enhance the pace of the reaction. Moreover, catalysts are not restricted to only gaseous reactions; they can also be effective in liquid-phase and solid-phase reactions, broadening their application across various fields of chemistry.