What foundational theories underpin chemical engineering, shaping its core principles and practices? From thermodynamics elucidating energy transfer within processes to transport phenomena governing mass and heat transfer, these theories are pivotal. The kinetic theory of gases delineates molecular behavior essential for reaction kinetics and reactor design. Fluid mechanics provides insights into fluid behavior, crucial for designing pipelines, pumps, and reactors. Additionally, quantum mechanics elucidates molecular structure and behavior, indispensable for understanding molecular interactions and material properties. Incorporating these theories, chemical engineers innovate processes, optimize production, and develop sustainable solutions across various industries, exemplifying the interdisciplinary nature of the field.