Examples of first order reactions

Some examples of reactions of first order are:

i. $\mathrm{2\,H_2O_2({\it l}) \longrightarrow 2\,H_2O({\it l}) + O_2(g)}$, $\;$ rate $= k\mathrm{[H_2O_2]}$

ii. $\mathrm{2\,N_2O_5(g) \longrightarrow 4\,NO_2(g) + O_2(g)}$, $\;$ rate $= k\,\mathrm{[N_2O_5]}$

In both cases the experimentally measured rate depends on the FIRST power of a single reactant's concentration, even though the balanced equations carry the coefficient 2 — a reminder that order is found from experiment, never read off the stoichiometry (section 6.3.2). Radioactive decay is another process that f …