Question 1: Define atom economy and explain why it is an important concept in sustainable chemistry.

Answer: Atom economy is a measure of the efficiency of a chemical reaction in converting reactants into desired products, calculated as the ratio of the molecular weight of the desired product to the total molecular weight of all reactants, expressed as a percentage. It is important because higher atom economy reduces waste and makes processes more sustainable.

Question 1: What factors influence the atom economy of a reaction?

Answer: Factors include the reaction pathway, the choice of reactants, and whether side reactions or by-products are minimised, affecting how efficiently reactants are converted into the desired product.

Question 2: Describe a reaction with high atom economy and one with low atom economy.

Answer: A reaction with high atom economy is the synthesis of ammonia via the Haber process, where most atoms in the reactants end up in the product. A reaction with low atom economy is the production of aspirin, which involves multiple steps and generates waste by-products.

Question 1: Calculate the atom economy for the reaction: C + O₂ → CO₂. Atomic masses: C = 12 g/mol, O = 16 g/mol.

Answer: Atom economy = (Molecular mass of desired product / Sum of atomic masses of reactants) × 100 = (44 / (12 + 32)) × 100 = (44 / 44) × 100 = 100%.

Question 2: A reaction involves 2H₂ + O₂ → 2H₂O. Calculate the atom economy. Atomic masses: H = 1 g/mol, O = 16 g/mol.

Answer: Desired product: H₂O, molecular mass = 18 g/mol. Total mass of reactants = (2 × 2) + 16 = 20 g/mol. Atom economy = (18 / 20) × 100 = 90%.

Question 1: Describe a theoretical experiment to test the atom economy of a reaction. Include variables you would control and safety precautions.

Answer: The experiment involves reacting known quantities of reactants and measuring the yield of the desired product. Variables to control include reactant purity, temperature, and catalyst presence. Safety precautions involve wearing protective gloves, goggles, and working in a well-ventilated area to handle hazardous chemicals safely.

Question 1: A chemical process produces two products, A and B. Product A has an atom economy of 85%, and product B has an atom economy of 60%. If 100 g of reactants are used, how much of each product can be optimally produced assuming 100% yield? Discuss which process is more sustainable and why.

Answer: Assuming 100% yield, product A would weigh approximately 85 g, and product B would weigh approximately 60 g, based on their atom economies. The process producing product A is more sustainable because it utilises reactants more efficiently with less waste, leading to a more environmentally friendly process.

Question 1: Explain how high atom economy reactions contribute to greener manufacturing processes in the pharmaceutical industry.

Answer: High atom economy reactions reduce waste and by-products, minimise resource consumption, and lower environmental impact, making pharmaceutical manufacturing more sustainable and eco-friendly.

Question 2: Identify one recent technological advancement that relies on high atom economy principles and describe its significance.

Answer: Green catalytic processes using recyclable catalysts exemplify advancements relying on high atom economy principles, significantly reducing waste and energy consumption in chemical manufacturing.