Since there is no hydrogen bromide in the inlet stream illustrated in Figure 9‐1, the steady‐state macroscopic balance provides the following result for hydrogen bromide
Here we see that measurements of the volumetric flow rate and the exit concentration of HBr provide an experimental determination of R
The concepts of local and global stoichiometry are illustrated in Figure 9‐2
where we suggest that hydrogen, H, and bromine, Br, may participate in the reaction at the local level, but may not be detectable at the macroscopic level.
Figure 9‐2. Production of hydrogen bromide: Local and global stoichiometry What is not detectable at the macroscopic level is often neglected, and we will do so in this first exploration of the hydrogen bromide reaction. This is indicated by the global stoichiometry shown in Figure 9‐2. At this point we assume that the reactor is perfectly mixed and this provides the simplification indicated by
A 1 , 2 , ..., N