Hi there, I am doing an experiment in increasing the mass of MnO2 when it is added to H2O2 decomposition, and I'm measuring the rate of temperature change. I chose increments of 0.050, 0.100, 0.150, 0.200, and 0.250 g to put into H2O2 when it is decomposed, i.e. the MnO2 is a catalyst. I noticed a generally increasing trend. I was wondering... I know that increasing the mass of the catalyst is just increasing the total surface area it has, but how exactly is surface area related to the rate of reaction?