01New path, lower barrier
A catalyst provides an alternate mechanism with lower activation energy. It speeds both forward and reverse reactions equally.
It does not change ΔH, K, or the amount of product — only how fast you get there. Enzymes, surface catalysts, and acid-base catalysts are all examples.
02Notebook box
Catalyst: Ea ↓, k ↑, ΔH same, K same.
Worked example: Adding a catalyst to an equilibrium mixture → equilibrium reached faster, same composition.