Answer in General Chemistry for Tayyaba riaz #156304
March 17th, 2023
How much electrical energy is required to generate 1.000L of H, at 25°C and 1.00 atm pressure by the electrolysis of water?
Redox reactions in water electrolysis :
Anode: 2H2O (l) = O2 (g) + 4H+ (aq) + 4e–
Cathode: 4H2O (l) + 4e– = 2H2 (g) + 4OH– (aq)
Reaction: 2H2O = 2H2 (g) + O2 (g)
n = PV/RT
n = (1.00 atm x 1.000 L)/(0.082 atm•L/mol•K x 298 K)
n = 0.041 mol
From reaction at cathode : mol ratio of electron and H2 = 4 : 2, so mol electrons :
= 4/2 x mol H2 = 2 x 0.041 mol = 0.082 mol
1 Faraday is the amount of electricity that is passed in the electrolysis cell to obtain 1 mole of electrons.
1 Faraday = 1 mole of electrons = 96500 Coulombs
So the energy required :