Controlling the Speed of Chemistry

Why do we refrigerate food? To slow down the chemical reactions that cause decay. Why do we use a catalyst in car exhausts? To speed up the breakdown of toxic gases. Every day, we control reaction rates without even thinking about it. Crushing a sugar cube makes it dissolve faster. Using hot water makes a stain easier to remove. These aren't random observations — they're predictable consequences of collision theory. Once you understand WHY each factor works, you can predict and control reaction speeds in any situation.