Explain how the concept of the mole, percent composition, empirical and molecular formulas and stoichiometry are used by chemical engineers to improve the efficiency of chemical reactions and reduce their negative impact on the environment and society.
All of these topics (stoichiometry, chemical formulas, moles, percent composition) are ways to track what happens to atoms during chemical reactions. Looking at the chemical formulas of the reactants and the products and the molar ratios of each of these species to each other shows exactly where all of the elements in the starting reactants eventually go to. By understanding exactly how a chemical reaction works, you can then find ways to maximize the desired product formation and minimize side product formation. The fewer side products that you make, the less waste you have to deal with at the end of the process. Also, the better you understand a reaction, the less solvent you need to make it work, thus producing less hazardous waste. The bottom line is the better you understand a reaction on the molecular level, the more efficient you can make the reaction work, produce less waste, and consume less electricity to operate the equipment.