Consider the reaction. 2 HBr(g) ¡ H2(g) + Br2(g) a. Express the rate of the reaction in terms of the change in concentration of each of the reactants and products. b. In the first 25.0 s of this reaction, the concentration of HBr drops from 0.600 M to 0.512 M. Calculate the average rate of the reaction during this time interval. c. If the volume of the reaction vessel in part b is 1.50 L, what amount of Br2 (in moles) forms during the first 15.0 s of the reaction?