A catalyst is a substance which speeds up a reaction, but is chemically unchanged at the end of the reaction. When the reaction has finished, you would have exactly the same mass of catalyst as you had at the beginning. Catalysts change the rate of the reaction (faster / slower) without being consumed (used up) in the reaction. They do this by providing a lower energy (easier) pathway from reactants to products. A catalyst works by providing a convenient surface for the reaction to occur. The reacting particles gather on the catalyst surface and 1) collide more frequently with each other 2) more of the collisions result in a reaction between particles because the catalyst can lower the activation energy for the reaction. B.H
Posted on: Fri, 02 Aug 2013 12:50:21 +0000