<p>Aqueous chromium trioxides form when Cr thin films are electrically stressed using a pair of sharp electrodes. The liquid oxide forms due to an electrochemical reaction, which is initiated from the tip of the cathode. This phenomenon is at the core of a cost-effective and carbon-efficient scanning probe-based patterning technique, known as Electrolithography (ELG). The liquid domain expands in a radially symmetric fashion, and the lateral spread can be controlled using several electrical and ambient parameters. A mathematical approach describing the expansion of the liquid region is yet to be proposed. Previous attempts in this direction have resulted in an electro-kinetic model, which has the drawback of not being able to agree with the experimental data in a single fit. In this article, we present an iterative model that helps us understand the progression of the liquid material over time. The model is defined with several parameters that have been related to the properties of the different chemical species in play. A prediction model is thereafter proposed and implemented in MATLAB with a high degree of agreement with the experimental data. The predictive model also incorporates a user interface for entering the values of different control parameters and produces an animated video to observe the material formation dynamically. The prediction model will thereby aid in optimizing the patterning process while performing ELG.</p>