Figure 3
Dependence of the time period of the chemical beat phenomenon (\(T_{{\text{b}}}\)) on the time period of one inflow rate (the time period of other inflow rate was fixed to 200 s) observed in the experiments in the acid–base neutralization reaction using sinusoidal time-dependent inflow rate functions of the reagents, acid \(\left( {r\left( t \right) = { }r_{0} + r_{{\text{A}}} {\text{sin}}\left( {\frac{2\pi }{{T_{{{\text{acid}}}} }}t} \right)} \right)\) and alkaline \(\left( {r\left( t \right) = { }r_{0} + r_{{\text{A}}} {\text{sin}}\left( {\frac{2\pi }{{T_{{{\text{base}}}} }}t + \varphi } \right)} \right)\) solutions with \( \varphi\) = π, \({ }r_{0}\) and \({ }r_{{\text{A}}}\) were 15 µL s−1. Blue and red symbols present the data when the time period of acid and base inflow rates was fixed (T = 200 s) once the time period of base and acid inflow rates was changed in the experiments, respectively. The concentrations of the acid and alkaline solutions in the input feed were 0.1 M (\(c_{{{\text{H}}^{ + } }}^{0} = c_{{{\text{OH}}^{ - } }}^{0} = 0.1 {\text{M}})\), respectively. The dashed lines represent the theoretically calculated curves from the relation \(T_{{\text{b}}} = \left| {1/\left( {\left( {T_{{{\text{acid}}}} } \right)^{ - 1} - \left( {T_{{{\text{base}}}} } \right)^{ - 1} } \right)} \right|\), i.e., \(f_{{\text{b}}} = \left| {f_{{{\text{acid}}}} - f_{{{\text{base}}}} } \right|\).
