how much electrical energy would it take to split 1 kg of water into hydrogen and oxygen?
446794
1 kg of water = 1000 grams of water.\nWater (H2O) has a molar mass of 18.02 grams per mol.\n1000 grams of H2O equals about 55.5 moles of water.\n\nThe reaction which water is split into Hydrogen gas and Oxygen as is as follows,\n2H2O (l) --electrolysis--> 2H2 (g) + O2 (g)\n\nThe change in the enthalpy of formation of this reaction equals about +571.8 kJ, meaning that at standard conditions and at a constant pressure, 571.8 kJ of work must be done on the system to totally split 2 moles of water into 2 moles of H2 and 1 mole of O2 gas.\nUsing this information, we find that to split 55.5 moles of water into 55.5 moles of H2 gas and 27.75 moles of O2 gas, it would require 15867.45 kJ of energy (or about 1.6 E7 Joules).\n\nThe amount of energy needed to split the water is also the maximum amount of energy which will be obtained if the H2 and O2 are then allowed to recombine again into water.
134371
Although some have talked about this, there are a lot of technical and practical questions to answer before this can happen. For example:\n\nWhat energy are you going to use to separate water into oxygen and hydrogen? \n\nHow are you going to store the hydrogen safely and dispense it? \n\nHow are you going to transport the hydrogeon?\n\nWill you keep the hydrogen liquid so it will not take up much room? \n\nHow will you keep the hydrogen liquid from warming up ? \n\nHow will you prevent terrible fires and explosions from accidents?\n\nWill you produce less pollution by using hydrogen, or more, given that you are having to use energy to create it? \n\nHow will you make the transition from petrochemical fuels to hydrogen fuels?\n\nWho is going to pay for this transition?\n\nHow are you going to build the very expensive infrastructure?\n\nProbably lots more questions too. Those are enough to start with, however.
125657
No, sadly. When you break down the chemical compund water, you would get Hydrogen in a gaseous state. You would have to compress it or cool it to bring it down to the temperature needed for it to condense into a liquid state.\n\nOh yeah, and I'm not sure, but I think the process is called electrolysis.
261005
Apparently groups in Sweden, Australia, and the UK are working on this. There are probably others as well. They are making progress. It does appear that this might allow the industrial scale separation of water into hydrogen and oxygen, and the reduction of atmospheric CO2. \n\n\nRecently, Jim Barber and So Iwata of Imperial College in London identified the actual crucial molecules that are used to split water by plants. This might lead to huge advances eventually. It is quite exciting.
1173693
WoW Dude! Hydrogen and oxygen BOTH in water! Now that is just so new-age and just today right? \nDamn Man! If you and I could just figure how to separate the two...\nSorry got lost in the thought! Please submit your picture to Ripley"s...
862439
The steam.  It would have to go through a phase change and give up a bunch of energy to turn back into water at 100.  Assuming you mean equal mass of water and steam. \n\nSame question for ice.  How much energy does it take to melt 1 Kg of ice at 0 to water at 0?
61416
Yes you could. Free hydrogen (H2) is rare in the atmosphere though, so you would have to buy industrially obtained hydrogen (which mostly comes from natural gas) which is expensive so its always cheaper to drill a water well or something. But yes, if you want to combine oxygen and hydrogen, and light it with a match, you will get water. Good luck trying to contain it after it goes from gas to the combustion product of hydrogen and oxygen, which will be water vapor (steam).
646959
2H2 + O2 ---- 2 H2O\n\nYou can easily obtain water around the house.
75209
I'll answer it, but you'd best pick me for the best answer if I'm doing all this work. ;)\n\nConvert C to K:\n\n178.0C = 451.15K\n25C = 298.15K\n30.6 = 303.75K\n\nTotal energy of water initially: Ei\n\nEi = 185.0g * 298.15K * 4.184J/g*K = 2.308E5 J\n\nTotal energy of water, final: Ef\n\nEf = 185.0g * 303.75g * 4.184J/g*K = 2.315E5 J\n\nEf - Ei = 700J\n\nLet Q be the specific heat of the alloy\n\nQ * 36.0g * 451.15K = Q * 36.0g * 303.75K + 700J\n\nQ*{(36.0g * 451.15K)-(36.0g * 303.75K)} = 700J\nQ = 700J/{(36.0g * 451.15K)-(36.0g * 303.75K)} \nQ = 700J/(16241g*K - 10935g*K)\nQ = 700J/3506g*K\nQ = 0.200 J/g*K
1031597
That 1kg of hydrogen would convert to about 0.954 kg of helium, the other 0.046 kg is changed to energy.\n\nE=MC^2\nM=0.046 kg\nC=300,000,000 m/s\nE=4.14X10^15 joules\n  = 1,150,000,000 Kilowatt-hours
987641
One of the best ideas is a device that uses the motion of the ocean waves to produce energy.  Also, it would be more efficient to simply burn hydrogen as a fuel source as opposed to trying extract the energy created when it bonds with oxygen to create water.  Another is simply burning garbage, I believe a major metropolitan city in Minnesota created a site to do this in the middle of downtown to show that it could be done with minimal side effects on the people living/working there.
336893
You've used 258.3kJ to boil the water.\n\nIf you use 2400 kJ/kg to turn water to steam, and you waste 50g of water then;\n\n=> 2400 / 1000 * 50 = 120 kJ\n\nTotal Energy used = 258.3 + 120 = 378.3 kJ
456100
How exactly are you splitting the H from the O?   Under high pressure and spraying?  I don't see how that could possibly work.  Cold fusion also has a huge potential for cheap, clean, renewable energy.  But much like what you are talking about, it simply isn't possible with the current technology.  If splitting H and O was so cheap and simple it would be done all of the time.  Electrolysis works, but the energy input makes it unrealistic for creating liquid hydrogen as an energy source.  If you truely have a way to spit the H20 molecule cheaply and efficiently you'd already be a multi-billionaire.
730140
The ice would gain 124.3 kJ in moving from -10 °C to zero.\nThe water would lose 252.0 kJ in moving from +10°C to zero.The difference in the two energies is sufficient to melt 383 g of ice.\nSo the mixture will be at 0 °C and will consist of 6383 g of water and 5617 g of ice.
166600
The idea is to add the acid to the water and then pass a current through the water.  The water will split into Hydrogen and Oxygen.  The bubbles of these gasses can collected in tubes, the H will produce twice as much gas as the O.\n\nThe rocket can be powered by igniting the hydrogen.\n\nI think the citric acid is more reactive than absorbic acid, but any thing will do including vinegar (acetic acid).
198671
Electrolysis. By applying electricity, you can break H2O into H2 and O2 gas.\n\n2H2O --> 2H2 + O2
749628
from my chemistry days we would use a 250 ml GLASS beaker and two GLASS testtubes to conduct electrolysis of water but it was only temporary the hydrogen would eventualy escape. now how to keep it pressurized is a little bit harder good luck finding that out.