"How does chemical engineering contribute to the design and optimization of industrial processes? Discuss the fundamental principles underlying unit operations like distillation, crystallization, and extraction. How do these processes aid in separating and purifying chemicals? Explain the role of chemical reactions in engineering design, focusing on concepts like stoichiometry, reaction kinetics, and thermodynamics. Lastly, how do engineers ensure safety and sustainability in chemical processes, considering factors like waste minimization and environmental impact?"