Hydrogen as Fuel: Sources and Fuel Cell Chemistry Steps: - Verify statement 1: Hydrogen is produced from water via electrolysis (2H₂O → 2H₂ + O₂) and from hydrocarbons via steam reforming (CH₄ + H₂O → CO + 3H₂), confirming both sources. - Verify statement 2: Fuel cells use H₂ and O₂ to produce electricity, water, and heat (2H₂ + O₂ → 2H₂O), directly generating power. - Verify statement 3: Fuel cell reaction involves H₂ oxidation at anode (H₂ → 2H⁺ + 2e⁻) and O₂ reduction at cathode (O₂ + 4H⁺ + 4e⁻ → 2H₂O), classifying it as redox. - Conclude all statements hold true based on established processes. Why D is correct: - All three statements align with the electrochemical definition of fuel cells, where H₂ sources include water/hydrocarbons and the core reaction (2H₂ + O₂ → 2H₂O) is a redox process producing electricity. Why the others are wrong: - A omits statement 3, but fuel cell reactions are inherently redox. - B omits statement 2, but H₂-O₂ reaction directly generates electricity in fuel cells. - C omits statement 1, …