Determination of Rate Constant for Enolization Reaction of Malonic Acid by Using Quartz Crystal Microbalance

We investigated the process of a bromination reaction of malonic acid (MA) in the Belousov-Zhabotinsky reaction by using a quartz crystal microbalance (QCM). That process involves an enolization reaction of MA as a rate-limiting reaction. We found that the variation of the Br2 concentration induces a shift of the viscosity and density of the solution in that process. This new finding led us to a determination of the reaction rate constant for the enolization reaction of MA due to the QCM measurement. This value measured by QCM is in good agreement with those measured by a spectrophotometer as described in previous reports. As a result, we succeeded to develop a new measurement method of the chemical reaction.