Question 1: Define a carboxylic acid and provide its general chemical formula.

Answer: A carboxylic acid is an organic compound containing a carboxyl group (-COOH). Its general formula is R-COOH, where R is a hydrocarbon group.

Question 2: Explain how carboxylic acids can be formed from alkenes in the context of industrial processes related to climate change mitigation.

Answer: Alkenes can be oxidised in the presence of oxygen and catalysts to produce carboxylic acids, such as the oxidation of ethene to ethanoic acid (vinegar), which can be used as a sustainable solvent or preservative, reducing reliance on fossil fuels.

Question 3: Describe the mechanism of oxidation of an alkene to a carboxylic acid.

Answer: The oxidation involves the addition of oxygen across the double bond of the alkene, initially forming an alcohol intermediate, which is further oxidised to a carboxylic acid through catalytic processes involving oxygen, often with the help of oxidising agents like potassium permanganate.

Question 1: Calculate the mass of ethanoic acid produced when 10 grams of ethene (C₂H₄) undergoes complete oxidation. (Molar mass of ethene = 28 g/mol; molar mass of ethanoic acid = 60 g/mol).

Answer: Approximately 21.4 grams.

Question 2: If 0.5 mol of methane (CH₄) is oxidised to produce carbon dioxide and water, how many moles of ethanoic acid can theoretically be produced if methane is converted through a process involving oxidation steps? (Hint: Consider the oxidation pathway and stoichiometry).

Answer: Approximately 0.25 mol, assuming complete oxidation to CO₂ and formation of acetic acid as a by-product.

Question 1: Design a simple experimental outline to demonstrate the oxidation of an alkene to a carboxylic acid, including safety precautions that should be observed.

Answer: The experiment involves adding an alkene, such as ethene, to a flask with potassium permanganate solution under controlled temperature. The reaction should be carried out in a well-ventilated fume cupboard, wearing safety goggles and gloves. The mixture turns from purple to colourless as the alkene is oxidised to a carboxylic acid. Proper disposal of chemicals and avoiding inhalation of fumes are essential safety measures.

Question 1: In a recent study, the emission of volatile organic compounds (VOCs), including carboxylic acids, increased in urban areas due to traffic pollution. Explain how the presence of carboxylic acids in the atmosphere can influence climate change.

Answer: Carboxylic acids in the atmosphere can contribute to the formation of secondary organic aerosols, which influence cloud formation and reflect sunlight, thereby affecting Earth's climate. They can also react with other pollutants, leading to smog formation and impacting air quality.

Question 1: Describe the environmental significance of producing carboxylic acids from alkenes in industry, particularly in relation to sustainable practices and climate change mitigation. (6 marks)

Answer: Producing carboxylic acids from alkenes allows for the synthesis of biodegradable chemicals like acetic acid, which can replace more harmful substances derived from fossil fuels. This process supports sustainable practices by reducing carbon emissions, minimising pollution, and enabling the development of eco-friendly products that help combat climate change.

Question 1: Explain how the industrial production of acetic acid from alkenes can contribute to reducing the carbon footprint compared to traditional methods.

Answer: The modern catalytic oxidation of ethene to acetic acid is more energy-efficient and produces fewer greenhouse gases than older methods like methanol carbonylation, thus reducing the overall carbon footprint and supporting environmentally sustainable chemical manufacturing.