Many designs of industrial reactors stem from designs from the 1960s-1970s. For a wide range of reactions, these designs lead to suboptimal reaction configurations due to limitations in heat- or mass-transfer. Process intensification has come up with a different approach, resulting in micro- and mini-reactors being safer and more cost-effective on a full industrial scale. However, based on the experience in the suboptimal reactor designs, the reaction rates of these reactions seem too low for full-scale reactions in a mini reactor. We suggest a test for the reaction rate based on a generalized model in combination with a specific type of mini-reactor: the rotor-stator spinning disc reactor. The generalized model is based on existing models on residence time distribution in such reactors. It does not need to be tailor-fitted for a specific rotor-stator spinning disc reactor that is used for the test, as is the case with current models. In this article, we show that our simplifications induce a difference in outcome in reaction rate of less than 10% with the existing models. Experiments with the well-studied chemical reaction of the hydrolysis of acetic anhydride show that the reaction rates calculated based on this scan fall within the range of reported data from the literature.