The residence time measurements are conducted by using the displacement marking method (step function), in which a tracer-free inlet flow is exchanged for a tracer flow (or vice versa) of the same flow rate at time t=0. The tracer-free solution contains the halide in tetrahydrofuran (THF), while 2 mol/L toluene is added to this solution for the tracer-containing solution. Unless otherwise specified, the measurement runs are performed by introducing the tracer toluene to the reactor system. For simultaneous Grignard reagent formation, the synthesis of phenylmagnesium bromide from bromobenzene and magnesium turnings is chosen. Coarse or fine magnesium turnings are used (refer to part 1 for the particle size distributions). Residence time measurements are started as soon as the Grignard reagent formation reaches a steady-state and full conversion of the halide is measured by IR and GC analysis. Measurement runs are repeated at least three times to obtain mean values for Bodenstein number Bo and mean residence time t̅ . The procedure for performing the residence time measurements and evaluation of the gathered data is described in detail in part 1.