Question 1: Define a chemical formulation and explain its importance in renewable energy applications.

Answer: A chemical formulation is a precise mixture of chemicals designed to produce specific properties or functions; in renewable energy, formulations ensure efficiency, safety, and environmental compatibility of energy systems.

Question 2: Describe why purity is critical in formulations used for hydrogen fuel cells.

Answer: High purity in formulations prevents contamination and ensures optimal performance and longevity of fuel cells, reducing chances of catalyst poisoning.

Question 3: Explain how the concentration of a chemical in a formulation can affect its effectiveness in renewable energy systems.

Answer: The concentration determines the amount of active substance, influencing the efficiency, reactivity, and stability of the energy system; incorrect concentrations can reduce performance or cause damage.

Question 1: A solution used in a hydrogen production process contains 50 grams of sodium hydroxide (NaOH) dissolved in 2 litres of water. Calculate the concentration in molarity. (Molar mass of NaOH = 40 g/mol)

Answer: Molarity = (Mass in grams / Molar mass) / Volume in litres = (50 / 40) / 2 = 0.625 mol/L

Question 2: A solar fuel cell requires a platinum catalyst with a purity of at least 99.9%. If a batch contains 500 grams of platinum with 0.2 grams of impurities, what is the purity percentage?

Answer: Purity % = [(Total weight - Impurities) / Total weight] × 100 = [(500 - 0.2) / 500] × 100 = 99.96%

Question 1: List three safety precautions to consider when preparing chemical formulations for hydrogen fuel cells.

Answer: Wearing appropriate PPE, working in a well-ventilated area, and handling chemicals with care to prevent leaks or explosions.

Question 2: Describe a basic procedure to prepare a dilute acid solution used in energy storage systems, including safety considerations.

Answer: Add the acid slowly to water while stirring to prevent splashing and heat generation. Use appropriate PPE, perform in a controlled environment, and dispose of waste safely.

Question 1: A sample of bioethanol used in renewable energy has a measured purity of 98.5%. If the sample weighs 200 grams, how much pure bioethanol is present?

Answer: Mass of pure bioethanol = 98.5% of 200 g = 0.985 × 200 = 197 grams

Question 2: A formulation for a solar panel coolant contains 5% sulphuric acid by volume. If a technician prepares 10 litres, how much sulphuric acid and water are needed?

Answer: Sulphuric acid = 5% of 10 L = 0.05 × 10 = 0.5 L; Water = 10 L - 0.5 L = 9.5 L

Question 1: Explain how the formulation of electrolyte solutions affects the efficiency of electrolysis in hydrogen production. Include considerations of purity and concentration. (6 marks)

Answer: Electrolyte formulations directly impact electrolysis efficiency by ensuring optimal ionic conductivity and minimal impurities. High purity electrolytes prevent catalyst poisoning and improve current flow, while correct concentration balances reactivity and energy consumption. Proper formulation reduces energy costs and increases hydrogen yield, making renewable hydrogen production more viable.

Question 1: Discuss the importance of chemical purity in the manufacturing of catalysts for solar energy devices.

Answer: High chemical purity in catalysts ensures maximum efficiency, reduces contamination, and prolongs device lifespan, which is critical for reliable and sustainable solar energy systems.

Question 2: Describe how formulations are tailored in biofuel production to optimise energy output and reduce environmental impact.

Answer: Formulations in biofuel production are adjusted to maximise fuel yield, improve combustion efficiency, and minimise impurities such as sulphur or nitrogen compounds. Using sustainable feedstocks and refining processes ensures reduced greenhouse gas emissions and environmental impact.