First order processes are of paramount importance for chemical kinetics. In a well-established demonstration experiment, the flow of water out of a vertical glass tube through a capillary simulates a chemical first order process. Here, a digital version of this experiment for lecture hall demonstrations is presented. To this end, water flowing out of the capillary is collected in a beaker which stands on an electronic scale interfaced with a computer. The computer generates a plot of the data in real time which is projected during the lecture. Hereby, with proper explanations, a very intuitive grasp of the essence of first order processes is obtained: The rate (represented by the water flow) is proportional to the concentration of the reactant (height of the water column). With a modified setup, consecutive first order kinetics as well as the concept of a rate-limiting step are illustrated.