In the previous chapter, we dealt with postulated products of a hydrocarbon chemical reaction for \(\Phi \le 1\) and for \(\Phi > 1\). The latter case was to be treated specially because it involves postulation of a two-step reaction mechanism (see Eqs. 3.46 and 3.47). The main point is that the postulated product composition was so far sensitized only to the value of \(\Phi \). The purpose of this chapter is to determine the effect of \(\Phi \), p and T on the product composition.