Fuel cells

10 questions on Fuel cells from the Electrochemistry chapter: 2 NEET level, 4 JEE Main, 4 JEE Advanced. Each one opens with its answer and solution.

• For H2(g) + 1/2 O2(g) -> H2O(l), Delta_r G deg = -237 kJ mol^-1 and Delta_r H deg = -286 kJ mol^-1. The maximum thermodynamic efficiency of a hydrogen-oxygen fu... JEE Main level
• Using Delta_r G deg = -237 kJ mol^-1 for H2 + 1/2 O2 -> H2O(l), the standard EMF of the hydrogen-oxygen fuel cell (in V, two decimals) is. JEE Main level
• Which statement about the hydrogen-oxygen fuel cell is NOT correct? NEET level
• In a hydrogen-oxygen fuel cell with concentrated aqueous KOH as electrolyte, the reaction at the cathode is NEET level
• A direct methanol fuel cell has the overall reaction CH3OH + 3/2 O2 -> CO2 + 2H2O. Which statements are correct? JEE Main level
• A hydrogen-oxygen fuel cell operates at a terminal voltage of 0.72 V. The electrical work obtained when 2.0 mol of H2 is consumed is (F = 96500 C mol^-1) JEE Main level
• A methane fuel cell is based on CH4(g) + 2O2(g) -> CO2(g) + 2H2O(l) with Delta_r G deg = -818 kJ mol^-1 and Delta_r H deg = -890 kJ mol^-1 at 298 K. Take F = 96... JEE Advanced level
• A hydrogen-oxygen fuel cell stack delivers 1.00 kW of electrical power at a terminal voltage of 0.800 V for 1.00 h. Find the volume of oxygen consumed, in litre... JEE Advanced level
• For the reaction H2(g) + 1/2 O2(g) -> H2O(l) at 298 K, Delta_r G deg = -237.1 kJ mol^-1 and Delta_r H deg = -285.8 kJ mol^-1. A hydrogen-oxygen fuel cell is bas... JEE Advanced level
• A hydrogen-oxygen fuel cell at 298 K is first run with pure O2 at 1 bar and then with air, in which the partial pressure of O2 is 0.21 bar. Hydrogen is at 1 bar... JEE Advanced level