The study of the kinetics of many reactions as well as simple probability suggests that most balanced equations do not literally describe how a reaction occurs in terms of the collisions made or the actual sequence of events.

The combustion of hexane illustrates this point:

2 C₆H₁₄ + 19 O₂ → 12 CO₂ + 14 H₂O

This reaction seems to imply that 2 hexane molecules and 19 oxygen molecules somehow collide simultaneously and fight it out among themselves until 12 carbon dioxides and 14 waters form. Right.

In Nature we observe lots of 2-body collisions, very few 3-body collisions and not much else. So chemists believe (backed up by experimental evidence) that reactions occur in a series of steps which are generally 2-body collisions. These steps add up to give the overall balanced equation and they must "agree" with the rate law. The steps are known as mechanisms.