8 Responses

1. Yes, same amount back. For some reason you also get a compound of nitrogen (forget which one) that causes smog. That’s why a fuel cell is better than direct burning- more usable power and less smog.

2. yes you get water. the same amount. but the question is, “Why would you ask?”

   it takes more energy to create the electrolysis than you get when you burn the hydrogen.
   to make it a continuous process, you have to keep adding electricity.
   you get no useful work out of the process.
   it’s a net energy consumer, not an energy producer.

3. If you take the products of the electrolysis, ie H2 and O2 and combine them and burn them then you get as much water as you started with. If you are doing this to store energy to run a vehicle, it is usual to keep only the H2 and release or sell the O2. Then, combining the H2 with air and burning it, you will still get the same amount of water back and the temperature of the combustion may cause some nitrogen compounds to form, written NOx, since the exact formulation is somewhat variable. By keeping the temperature of the combustion down, say by also injecting a little water with the mix, it is possible to greatly reduce the amount of NOx created, as it is a high temperature process.
   The advantage of doing this is that the hydrogen gas can be stored, as a pressurized gas, a metal hydride, or even liquid hydrogen, although that in particular is itself energy intensive, difficult to do and dangerous for the average person to handle. Pressurized H2 gas storage is more like working with propane, which most people are capable of doing, although the cylinder is much larger, since it is not liquid and so must be a high pressure container to hold a useful quantity.

4. you get back the same amount of water, provided you have collected all the hydrogen (without it escaping into the atmosphere) and completely burnt it , that is has all the oxygen needed for it (hydrogen) to burn…. but do not try it at home– hydrogen burning is highly explosive and dangerous

5. Water. There are trace amounts of CO2 and even smaller amounts of NO2 Due to the oil used to lubricate the engine. But, they are in such small amounts that you don’t need a catalytic converter. There will also be releases of metals as the internal friction of the motor causes wear. A fuel cell that runs on Hydrogen is the best answer. It is more efficient due to very little heat loss and no moving parts. There is a company now that claims to have made a Fuel cell that runs off of natural gas. So far though this technology is not available to the public. Nasa has been using fuel cells on the space shuttle and space station since the 80’s. But, these fuel cells cost more than a million to produce. Making it not cost effective for the average person. The car of the future will be one that has a solar panel on the roof of the garage that produces compressed Hydrogen. A car that has a tank of compressed hydrogen and uses a fuel cell to convert hydrogen to water. In exchange producing electricity. That electricity then is used to power an electric motor. Making the average car quiet. Effecient. And with a range of 600 mile per tank. Then, we can have hydrogen fill up stations along the road so you can pay to fill your car when you travel.

6. You’re right. Pure water can be separated into two parts hydrogen and one part oxygen. and when ignited these same gasses will obligingly combine to form the same amount of water that you started with. That is precisely the reaction that produced those dazzling white clouds when the space shuttle went up, and that which powers Arnold Schwarzenegger’s quarter million dollar rolling publicity stunt.

   The problem is you have to expend energy to separate the water, which must come from somewhere, and those nasty old thermodynamics laws dictate that you can’t possibly recover as much energy from burning hydrogen as it took to free it from the water. Having seen how carelessly so many of my fellow primates handle gasoline I’m really not all that keen on being anywhere in the vicinity when they fill up with super cold, potentially explosive liquid hydrogen, not to mention that a fuel tank rupture a la the Ford Pinto could take out a city block.

   So, at least for the foreseeable future, I’m afraid the hydrogen-powered economy must be relegated to the possible-but-not-practical category.

7. yes you get same amount of water and oxygen and some nitrogen.

8. no..little less