Question 1: Hydrogen fuel cells convert chemical energy directly into electrical energy through a chemical reaction between hydrogen and oxygen. This process produces electricity, water, and heat. Understanding how these cells work is essential for developing sustainable energy sources.

Answer: Hydrogen fuel cells generate electricity through a chemical reaction between hydrogen and oxygen, producing water and heat as byproducts.

Question 1: Define a hydrogen fuel cell and explain its basic working principle.

Answer: A hydrogen fuel cell is a device that converts hydrogen and oxygen into electricity through electrochemical reactions, producing water as a byproduct.

Question 2: Write the overall chemical equation for the reaction in a hydrogen fuel cell.

Answer: 2H₂ + O₂ → 2H₂O

Question 3: Identify the two main electrodes in a hydrogen fuel cell and describe their functions.

Answer: The anode, where hydrogen is oxidized, and the cathode, where oxygen is reduced, allowing electron flow to generate electricity.

Question 1: If a hydrogen fuel cell consumes 3 mol of hydrogen gas (H₂) per minute, calculate the amount of water produced in grams per minute. (Molar mass of H₂O = 18 g/mol)

Answer: 54 grams

Question 2: A hydrogen fuel cell has an output voltage of 0.8 V and operates at a current of 10 A. Calculate the power output in watts.

Answer: 8 watts

Question 1: Describe a simple experiment to demonstrate the production of water from hydrogen and oxygen gases. Include safety precautions.

Answer: Experiment: Mix hydrogen and oxygen gases in a safe container and ignite with a spark. Observe the formation of water droplets or condensation. Safety precautions include conducting the experiment in a well-ventilated area, wearing safety goggles, and avoiding open flames near gas sources.

Question 2: Explain two environmental benefits of using hydrogen fuel cells instead of fossil fuels.

Answer: Hydrogen fuel cells produce only water as a byproduct, reducing air pollution, and they can be powered by renewable hydrogen, reducing greenhouse gas emissions.

Question 3: Hydrogen fuel cells are considered a sustainable energy source. Which of the following is a major challenge in their widespread adoption? (Options: a) Cost of hydrogen production, b) Lack of safety measures, c) Limited water availability, d) Excessive noise)

Answer: a) Cost of hydrogen production

Question 1: Describe how hydrogen fuel cells are used in transportation, providing at least one example.

Answer: Hydrogen fuel cells are used in fuel cell electric vehicles (FCEVs), where they power the electric motor, offering a clean alternative to gasoline-powered cars.

Question 2: Predict one future development or improvement in hydrogen fuel cell technology and its potential impact.

Answer: Future developments may include reducing the cost of hydrogen production and improving storage methods, which could make hydrogen fuel cells more affordable and widespread, leading to a significant decrease in carbon emissions from transportation and industry.