2006-07-01 13:45:29 · 3 answers · asked by fusionh2wlh 2 in Science & Mathematics ➔ Chemistry
1 kg. of hydrogen contains 6x10^26 atoms. To liberate 1 atom of hydrogen requires 1 electron, so you need 6x10^26 electrons. 1 electron is 1.6x10^ -19 coulombs of electric charge. So 6x10^26 electrons is 96 million coulombs; that is, 96 million amp seconds, or, say, 10 amps flowing for 9.6 million seconds. When you burn 1 kg hydrogen you get 9 kg of water and release 2600 megajoules of heat. So the opposite process, splitting 9 kg of water to release 1kg hydrogen requires 2600 megajoules of electricity, or 722 kilowatt hours of electricity. You'd actually need a little bit more, because some of the electrical energy is used up heating the water.
2006-07-01 14:10:27 · answer #1 · answered by zee_prime 6 · 0⤊ 0⤋
More than you would get back if you were planning on burning the hydrogen.
2006-07-01 13:49:22 · answer #2 · answered by Mr. Peachy® 7 · 0⤊ 0⤋
Electrolysis of water :
2H2O(l)--> 2H2(g) +O2(g)
mole ratio =1:1
energy required = 474.4kJ
1000gH2(1molH2/2.016gH2)=
496.03molH2(474.4kJ/1molH2)=
235317kJ or 235.megaJ
2006-07-02 07:01:12 · answer #3 · answered by bige1236 4 · 0⤊ 0⤋