Understanding of chemical reactivity is founded on the fundamental concepts of Electrophilicity and Neucleophilicity. All extant attempts to do this depend on the reaction of molecular species where the unwanted steric effects complicate the measurements. Muonium with its minimum steric requirements are well suited to provide the kinetic measurements needed for such a quantificatioin. The unique RF-MuSR facility at ISIS provides a way of measuring site speific absolute rates of addition of muonium. We wish to explore this possibility by using the compound benzoic acid where the hyperfine parameters are already available in the literature. In a recent experiment (RB1110259) we have shown that in ethanol solution the muonium addition rates to benzoic acid to be well within the range for RF-MuSR measurement. We now request beamtime to carry out the RF-MuSR to complete this study.