In chemical engineering, the fundamental theories serve as the bedrock for understanding processes and phenomena. These theories encompass principles from physics, chemistry, and mathematics, providing the framework for designing and optimizing chemical processes. From thermodynamics to fluid mechanics, kinetics to transport phenomena, these theoretical foundations elucidate the behavior of chemical systems at various scales. Mastery of these theories empowers engineers to tackle challenges in diverse industries, from pharmaceuticals to petrochemicals, ensuring efficient and sustainable production processes.