What are the fundamental principles underlying chemical engineering, and how do they contribute to the design and operation of chemical processes? Discuss key concepts such as mass and energy balances, reaction kinetics, and transport phenomena, elucidating their significance in engineering design and problem$-$solving. Explore the application of these principles in various industries, including pharmaceuticals, petrochemicals, and food processing, highlighting their role in optimizing process efficiency, product quality, and safety. Additionally, analyze the importance of sustainability and environmental considerations in chemical engineering practice, emphasizing the need for green and eco$-$friendly process design solutions.