Catalyst vs Inhibitor: What's the Difference?
If a catalyst speeds a reaction up, an inhibitor must be its mirror image and slow it down, right? Half right — and the half that's wrong is exactly where exam marks get lost. The short answer: a catalyst speeds a reaction up by offering an alternative route with a lower activation energy, and is regenerated unchanged at the end. An inhibitor slows a reaction down — usually by blocking or removing something the reaction depends on — and is very often used up in the process. Quick comparison at a glance Feature Catalyst Inhibitor Effect on rate Increases it Decreases it How it works Provides a lower-activation-energy pathway Blocks a site, removes a reactive intermediate, or poisons a catalyst Consumed overall? No — always regenerated Depends on the type; many are used up Amount needed Tiny, often catalytic traces Usually far more than a catalyst Effect on equilibrium position None None (it changes only how fast equilibrium is reached, if at all) Effect on activation ene...