Chemistry questions

[Newc]

For you Chemistry Majors out there, all this talk about using hydrogen for fuel got me thinking:

Water can be separated into its base elements - Hydrogen and Oxygen.
The Hydrogen is used as fuel, and the Oxygen is released into the atmosphere.

Oxygen can burn as well, correct? Or is that a specific type of Oxygen (respirators and such that have labels warning against open flame)?

How much Hydrogen and Oxygen can be extracted from 1 gallon of water?

Since water is made of 2 parts Hydrogen and 1 part Oxygen, can you convert 1 gallon of water to 2 gallons of hydrogen and 1 gallon of oxygen? If so, and if oxygen can be burned as fuel, that's 3 gallons of fuel right there.

[shobet]

I think there is an energy cost in extracting the hydrogen, I've had to many gin and tonics to recall it correctly but I'm sure someone will pipe up with an answer.

[scotty]

Something like this? http://youtube.com/watch?v=6Rb_rDkwGnU

[Nazgul]

wouldn't that be more like 2/3 gallons of hydrogen and 1/3 gallon of oxygen?

[Norton]

For you Chemistry Majors out there, all this talk about using hydrogen for fuel got me thinking:

Water can be separated into its base elements - Hydrogen and Oxygen.
The Hydrogen is used as fuel, and the Oxygen is released into the atmosphere.

Oxygen can burn as well, correct? Or is that a specific type of Oxygen (respirators and such that have labels warning against open flame)?

How much Hydrogen and Oxygen can be extracted from 1 gallon of water?

Since water is made of 2 parts Hydrogen and 1 part Oxygen, can you convert 1 gallon of water to 2 gallons of hydrogen and 1 gallon of oxygen? If so, and if oxygen can be burned as fuel, that's 3 gallons of fuel right there.

Oxygen can't be burned as fuel. But it's needed to get the burning reaction going.

Burning is simply, oxidating, as you know.

[rjohnstone]

It actually takes more energy to extract Hydrogen from water than the energy it can produce.
Oxygen in and of itself is not a good fuel. It can increase the energy output of an existing fuel like gas (think Nitrous Oxide), but by itself, it's not to good.

It's easier to extract Hydrogen from Methane, but whats the purpose. Methane has more energy output than Hydrogen alone.

[Newc]

It's my understanding that hydrogen doesn't need oxygen to burn (see the Sun).

Not much reliable info around the net. Here's an interesting article that seems extremely suspect:

http://netmar.com/~maat/archive/watercar/h20car2.htm

Note they state early on that Hydrogen burns clean (no fumes/vapors), yet they had to open the garage doors to run the engine used in the demonstration for ventilation.
Ventilation of what? The non-existant emissions?

It actually takes more energy to extract Hydrogen from water than the energy it can produce.

But it's not like it takes 12 car batteries at once to extract 3 ounces of hydrogen.

[Norton]

The hydrogene in the sun doesn't burn. It makes a fusion reaction and turns into Helium.So, the sun is "nucular", as George W. Bush would say


You need oxygen to burn anything. But it's not a fuel.

[rjohnstone]

True.. the Sun doesn't "burn". It is a nuclear reactor.
What you see is plasma, not actual "fire".

[Norton]

True.. the Sun doesn't "burn". It is a nuclear reactor.
What you see is plasma, not actual "fire".

Yeah, it's Jimi Hendrix kinda fire

[thetroy]

It actually takes more energy to extract Hydrogen from water than the energy it can produce.
Oxygen in and of itself is not a good fuel. It can increase the energy output of an existing fuel like gas (think Nitrous Oxide), but by itself, it's not to good.

It's easier to extract Hydrogen from Methane, but whats the purpose. Methane has more energy output than Hydrogen alone.

This is correct. People always seem to forget that it takes energy to get all of these fuels (whether we mean batteries, gasoline, hydrogen, whatever)

[Shawn Lutz]

True.. the Sun doesn't "burn". It is a nuclear reactor.
What you see is plasma, not actual "fire".

its fuggin hot too :ROTF:

[rjohnstone]

its fuggin hot too :ROTF:

A nasty, albeit useful, side effect to that whole fusion thing.
Puts off a fair amount of light too.

[GodOfRhythm]

Hydrogen as a fuel is basically bullcrap. They should focus on finding a way to conserve superfluous electricity in a more efficient manner than elektrolysing water to create hydrogen.

The whole helium-3 hype comes to mind. I don't care what anyone says, I'm investing in helium-3 in about 5 years!

[MetalGrasshopper]

The energy required to separate oxygen and hydrogen is larger than the output energy of hydrogen so its impossible for only water to perpetually power a vehicle.

You need something to react with the oxygen in order for there to be any sort of combustion. Most of the energy released from combustion is usually from a hydrocarbon (propane, octane, butane, etc.) being reacted with oxygen, so the energy isn't only from oxygen but rather most of it is from the hydrocarbon being combusted.

1 Gallon of water would theoretically yield about 4700 liters of hydrogen, and 2350 liters of oxygen.