Sciencemadness Discussion Board

Rule for relationship between catalyst concentration and reaction rate?

RareEarth - 24-7-2015 at 06:24

I was doing a bit of reading on this and what I gathered was for homogeneous reactions, reaction rate is directly proportion to cat. concentration. For heterogeneous reactions, I couldn't get much of a clear answer, other than that cat. surface area played a role.

This makes sense for homogeneous reactions, but I am not so sure about heterogeneous reactions. What about conditions where the reactants are homogeneous, and the catalyst is in the solid phase? Logic would suggest in that latter case that reaction rate would be proportional to the catalyst.

For multi-phasic reactions, it would seem to be inherently limited by some factor of the stir rate and catalyst concentration.

blogfast25 - 24-7-2015 at 08:15

Consider the catalyst to be a reagent that is constantly being regenerated, so it's concentration or surface area is constant. Then simply apply the relationship between concentration/surface area and reaction rate, for general reagents.