How do you find a step that has the largest rate constant in the forward reaction? When looking at a potential energy diagram

Answer 1

Am I not right that the PE diagram tells you what energy level must be attained (and the activation energy) to allow a reaction to occur BUT it never tells you the rate

Answer 2

Are you asking about 'rate determining step' in a reaction mechanism... e.g., Sn1 mechanism of t-BuBr?