Do the reaction rate depends on the concentration of catalyst?
I googled this and found that the decomposition of H2O2 stops of we add excess MnO2.
Are there any other examples like this? Or does this happens with every catalyst when they are in excess or they are in very smaller amounts?(But I've learned that a very small amount of the catalyst is usually needed to increase the reaction rate)
2 answers
I think you misunderstood the site where you obtained that information. A catalyst does speed up the reaction and only minimum amounts are needed. Increasing the catalyst increases the rate UP TO A POINT. When you say increasing the amount of catalyst STOPS if we add excess MnO2, this means THE REACTION RATE STOPS INCREASING. It doesn't mean that it shuts down the decomposition of H2O2. The decomposition still takes place, you've simply reached the point at which more and more MnO2 has no effect on the rate; i.e., you have reached the maximum rate of decomposition. I hope that is clear enough to you although the wording sounds a little awkward to me. But I didn't want to rewrite it.
I understand and thank you very much!
0 answers