A fuel cell produces 0.448 L of H₂O vapor (STP) at the cathode from O₂. How many coulombs are involved? (F = 96500 C/mol
Cathode: O₂ + 4H⁺ + 4e⁻ → 2H₂O . 2 mol H₂O (44.8 L) requires 4F. Moles = (0.448/22.4) = 0.02 mol , Charge = (0.02/2) × 4 × 96500 = 0.04 × 96500 = 3860 C .
Ref: NCERT Class 12 Chemistry > Chapter 2: Electrochemistry > Topic: Batteries - Primary Secondary and Fuel Cells