Batch mixing with chemical reaction in the laminar flow regime was studied using a helical ribbon impeller and a Newtonian fluid. A chemical reaction between crystal violet dye and sodium hydroxide was used, with the progress of the reaction being followed by means of a spectrophotometer. Comparison of the experimental circulation time results with other experimental data from the literature and with results obtained from numerical simulation showed good agreement. Good agreement was also obtained with experimental results obtained using a thermal response method. The dimensionless mixing time, defined as the point at which the concentration reached 95% of its ultimate value in the absence of chemical reaction, was found to be 10 times the dimensionless circulation time.