“…It appears that reaction (4) plays a part in H0N0 2 formation early in the experiment when the hydroxyl concentration is at its highest, however most of the nitric acid is formed after NO 2 has reached its peak and O3 has begun to accumulate. Hence reactions (1)(2)(3) are the predominant source of H0N0 2 . This observation is also supported by the fact that almost all investigators report a good nitrogen balance up to the time when NO 2 maximizes.…”