What Is a Catalyst? How Reactions Get a Shortcut
Some reactions that should happen barely crawl along — until you add a pinch of the right substance and they suddenly race. That substance isn't a reactant and it isn't used up. It's a catalyst, and it's one of the most useful tricks in all of chemistry (and biology). The short answer: a catalyst is a substance that speeds up a chemical reaction by providing an easier pathway with a lower activation energy , without being permanently used up itself. Because it's regenerated at the end, a tiny amount of catalyst can help enormous amounts of reactant react, over and over. What a catalyst actually does Every reaction has an energy "hill" the reactants must climb before they can turn into products — the activation energy . A catalyst doesn't push the reactants harder; it offers a lower hill by giving the reaction an alternative route. More reactant particles have enough energy to get over a smaller hill, so the reaction goes faster. An analogy: ima...