So at the same temperature we're going to use the same reactant for some given reaction. Now, if we change our reactants, we're also going to have to change our KF because our rate constant also depends on the types of reactants used. Now, one last thing I want to mention is that this rate law, this equation is determined strictly using experimental results. That's the only way we can determine this relation. We can't determine this relation using the formula above.