Data from: Mathematical modelling of the vitamin C clock reaction

Chemical clock reactions are characterised by a relatively long induction
period followed by a rapid `switchover' during which the
concentration of a \emph{clock chemical} rises rapidly. In addition to
their interest in chemistry education, these reactions are relevant to
industrial and biochemical applications. A substrate-depletive,
non-autocatalytic clock reaction involving household chemicals (vitamin C,
iodine, hydrogen peroxide and starch) is modelled mathematically via a
system of nonlinear ordinary differential equations. Following dimensional
analysis the model is analysed in the phase plane and via matched
asymptotic expansions. Asymptotic approximations are found to agree
closely with numerical solutions in the appropriate time regions.
Asymptotic analysis also yields an approximate formula for the dependence
of switchover time on initial concentrations and the rate of the slow
reaction. This formula is tested via `kitchen sink chemistry'
experiments, and is found to enable a good fit to experimental series
varying in initial concentrations of both iodine and vitamin C. The
vitamin C clock reaction provides an accessible model system for
mathematical chemistry.