The problem statement, all variables and given/known data So I'm doing a lab report on the reaction of food dye with bleach. I have a couple of questions: 1) What's the difference between pseudo rate constant and rate constant?? (i.e. k' vs. k) 2) How do I write the rate law for this reaction? I graphed the data and found the reaction order with respect to dye to be 1 and then comparing the changes in k' with respect to the changes in bleach concentrations revealed that the order with respect to bleach was also 1. The pseudo rate constant was 0.1669 (the average slope of all the trials). How do I go about writing the rate law? In the explanation it says that the rate law simplifies to Rate = k'[D]^m (where D is the dye) because there is a large excess of bleach present. The attempt at a solution I think the rate law should be Rate = k[D][OCN-] But I'm not sure if the pseudo rate constant can be just substituted as k. and the partial orders for each should be 1 because that's what I found the orders with respect to Dye and OCN ions. Is that correct?