Two reactions which speed each other up Recently I have started looking for two reactions that would speed each other up. That means that the products of the first reaction accelerate the second one, and in turn, the products formed in the second reaction accelerate the first one. Do you know any examples of such reactions?
Have a look at some non-linear reaction schemes such as gas phase radical chain reactions that may lead to explosion. The propagation steps in the hydrogen/bromine gas phase reaction do what you suggest:

$$\begin{align}
\ce{H^. + Br2 &amp;-&gt; HBr + Br^.} \\
\ce{Br^. +H2 &amp;-&gt; HBr + H^.}
\end{align}$$