Question 1: Explain briefly how a hydrogen fuel cell produces electricity and why it is considered environmentally friendly.

Answer: A hydrogen fuel cell produces electricity by combining hydrogen and oxygen to form water, releasing electrical energy in the process. It is environmentally friendly because it produces no greenhouse gases during operation, only water vapour.

Question 1: Define a hydrogen fuel cell and describe its main components.

Answer: A hydrogen fuel cell is a device that converts chemical energy from hydrogen into electrical energy through electrochemical reactions. Its main components are an anode, a cathode, and an electrolyte membrane.

Question 2: Describe the chemical reaction that occurs at the anode and cathode in a hydrogen fuel cell.

Answer: At the anode, hydrogen molecules are split into protons and electrons: 2H₂ → 4H⁺ + 4e⁻. At the cathode, oxygen reacts with electrons and protons to form water: O₂ + 4H⁺ + 4e⁻ → 2H₂O.

Question 1: A hydrogen fuel cell operates with a voltage of 0.7 V and produces a current of 50 A. Calculate the power output in watts.

Answer: Power = Voltage × Current = 0.7 V × 50 A = 35 W

Question 2: If a hydrogen fuel cell produces 35 W of power continuously for 2 hours, how much energy is generated in kilowatt-hours (kWh)?

Answer: Energy = Power × Time = 0.035 kW × 2 hours = 0.07 kWh

Question 1: Outline the key variables you would control and measure in this experiment, and list two safety precautions to consider.

Answer: Variables to control include hydrogen flow rate and temperature; to measure efficiency, record voltage and current output. Safety precautions include ensuring proper ventilation to prevent hydrogen accumulation and wearing protective equipment to handle gases safely.

Question 1: A hydrogen fuel cell produces a voltage of 0.8 V and a current of 40 A when operating under standard conditions. Calculate the power output and discuss what this indicates about the cell’s efficiency.

Answer: Power = 0.8 V × 40 A = 32 W. This indicates that the fuel cell is generating a significant amount of electrical energy, and its efficiency can be further analysed by comparing input chemical energy to electrical output.

Question 1: Evaluate the potential of hydrogen fuel cells to reduce greenhouse gas emissions compared to traditional fossil fuel-powered vehicles. Include environmental, economic, and technological considerations in your answer.

Answer: Hydrogen fuel cells offer a promising way to reduce greenhouse gases because they produce only water vapour during operation, unlike fossil fuels which emit CO₂. Environmentally, they help mitigate climate change. Economically, the cost of producing and storing hydrogen is a challenge, but advances in technology could make fuel cells more affordable. Technologically, infrastructure development is needed for widespread adoption. Overall, they represent a sustainable alternative that can significantly lower carbon footprints if these challenges are addressed.

Question 1: Identify two current applications of hydrogen fuel cells in industry or transportation, and explain how they contribute to reducing environmental impact.

Answer: Hydrogen fuel cells are used in fuel cell electric vehicles (FCEVs) and backup power systems. They contribute to reducing environmental impact by producing zero tailpipe emissions and decreasing reliance on fossil fuels, thus lowering overall greenhouse gas emissions.