Question 1: Atom economy is a measure of how efficiently a chemical reaction converts reactants into desired products. It is expressed as a percentage and helps assess the environmental impact of a reaction.

Answer: Atom economy measures the efficiency of a reaction in converting reactants into useful products, indicating how environmentally friendly and cost-effective the process is.

Question 1: Define atom economy in the context of chemical reactions.

Answer: Atom economy is the percentage of the total atomic mass of reactants that ends up in the desired product.

Question 2: Describe two factors that can influence the atom economy of a chemical reaction.

Answer: Factors include the reaction mechanism, choice of reactants, and whether side reactions or by-products are minimised.

Question 3: Explain why high atom economy is desirable in industrial chemical manufacturing.

Answer: High atom economy reduces waste, lowers costs, and minimises environmental impact, making processes more sustainable.

Question 1: A reaction between hydrogen and nitrogen produces ammonia. The molar masses are H₂ = 2 g/mol, N₂ = 28 g/mol, and NH₃ = 17 g/mol. Calculate the atom economy of this reaction.

Answer: Atom economy = (Mass of desired product / Total mass of reactants) × 100 = (17 g / (2 g + 28 g)) × 100 ≈ 53.1%

Question 2: In the synthesis of ethanol (C₂H₅OH), the main reaction uses ethene (C₂H₄) and water. The molar masses are C₂H₄ = 28 g/mol, H₂O = 18 g/mol, and C₂H₅OH = 46 g/mol. Calculate the atom economy assuming complete conversion to ethanol.

Answer: Atom economy = (46 g / (28 g + 18 g)) × 100 ≈ 80.6%

Question 1: Outline the key variables that must be controlled in a laboratory experiment to accurately determine the atom economy of a reaction.

Answer: Variables include reactant purity, reaction conditions (temperature, pressure), reaction completeness, and measurement accuracy.

Question 2: Identify two environmental benefits of designing chemical processes with high atom economy.

Answer: Reduced waste and emissions, lower resource consumption, and decreased environmental pollution.

Question 3: Discuss how improving atom economy can influence the economic costs of chemical manufacturing.

Answer: Improving atom economy can reduce raw material costs, decrease waste disposal expenses, and increase overall process efficiency, leading to lower production costs and higher profitability.

Question 1: A certain industrial process produces a desired product with an atom economy of 65%. If the process uses 100 kg of reactants, estimate the maximum mass of the product that can be obtained assuming ideal conditions.

Answer: Maximum mass of product = (Atom economy / 100) × total reactant mass = (65 / 100) × 100 kg = 65 kg.

Question 2: Explain how improving the atom economy of a pharmaceutical synthesis can benefit both the environment and the pharmaceutical industry.

Answer: Higher atom economy reduces waste and hazardous by-products, lowering environmental impact. It also decreases raw material costs and increases yield, making the process more sustainable and cost-effective for industry.