Question 1: Define atom economy and explain why it is important in green chemistry.

Answer: Atom economy is a measure of the efficiency of a chemical reaction, calculated as the ratio of the mass of desired product to the total mass of all reactants, expressed as a percentage. It is important because it minimises waste, reduces costs, and makes chemical processes more environmentally sustainable.

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

Answer: Factors include the reaction pathway, the efficiency of the reaction, the formation of by-products, and whether the reaction is optimised to produce minimal waste.

Question 2: Describe how a reaction with high atom economy benefits the environment.

Answer: High atom economy reactions produce less waste, reduce pollution, lower raw material consumption, and are more sustainable, thereby benefiting the environment.

Question 1: The synthesis of ammonia (NH₃) from nitrogen and hydrogen: N₂ + 3H₂ → 2NH₃. Given that the molar masses are N = 14 g/mol, H = 1 g/mol, calculate the atom economy for this reaction.

Answer: Atom economy = (Mass of desired product / Total mass of reactants) × 100 = (2 × 17 g / (28 + 3 × 2 g)) × 100 = (34 g / 34 g) × 100 = 100%.

Question 2: In the production of ethanol (C₂H₅OH) from ethene (C₂H₄) and water, the reaction is C₂H₄ + H₂O → C₂H₅OH. Given molar masses: C = 12 g/mol, H = 1 g/mol, O = 16 g/mol, calculate the atom economy.

Answer: Atom economy = (C₂H₅OH / (C₂H₄ + H₂O)) × 100 = (46 g / (28 + 18 g)) × 100 = (46 g / 46 g) × 100 = 100%.

Question 1: Describe a theoretical experiment to compare the atom economy of two different synthesis methods for producing a salt. Include variables to control and safety precautions.

Answer: Students should outline comparing two synthesis routes, controlling variables such as temperature, pressure, and reactant purity. Safety precautions include wearing protective gear, handling chemicals in a fume hood, and proper waste disposal. The experiment involves measuring mass of reactants and products to calculate atom economy for each method.

Question 1: A new catalytic process claims to increase the atom economy of producing a certain pharmaceutical compound from 60% to 85%. Discuss the potential environmental and economic benefits of this improvement.

Answer: An increase in atom economy from 60% to 85% means less waste and more efficient resource use. Environmentally, this reduces pollution and raw material consumption. Economically, it lowers costs associated with raw materials, waste management, and disposal, making the process more sustainable and profitable.

Question 1: Provide an example of a commercial product or industry that benefits from high atom economy processes, and explain why.

Answer: Pharmaceutical manufacturing benefits from high atom economy processes because they produce fewer waste by-products, reduce costs, and make the production more environmentally friendly.