But now we're going to have to take this guide into consideration from the first step. So let's write the rate determining or let's write the rate law for our first step. So remember, we're dealing with an elementary bimolecular reaction, the first step as well as a second step. So we can write our rate laws in the following manner. The rate of the first step is equal to k one. Our constant going this way times the concentration of this guy to the first power because we have a coefficient of one times the concentration of BR also to the first power because we have a coefficient of 1 mol.