This experiment and analysis offer an economic yet challenging semi-batch reactor experience. Household bleach is pumped at a controlled rate into a batch reactor containing pharmaceutical hydrogen peroxide solution. Batch temperature, product molecular oxygen, and the overall change in solution conductivity are metered. The reactor simulation combines published kinetics and molar conductivities with species and energy balances to predict the evolved oxygen rate, batch conductivity, and temperature. Comparisons between data and model are reasonably good.