Water is to heavy

[droopy1592]

If you are talking about weight and not mass, carrying the oxygen and hydrogen around in gaseous form would save you a lot.

They would still have the same mass but much more volume.

 

[droopy1592]

Water would actually be very slightly lighter than separated hydrogen and oxygen, because bonded molecules are in a lower energy state (this is why there's an explosion when you mix hydrogen and oxygen).

As for Deuterium/Tritium, the difference is pretty small. Consider that the oxygen atom in the water molecule has an atomic weight of 16. The hydrogen atoms will usually have atomic weights of 1. Deuterium and tritium have atomic weights of 2 and 3, respectively. So, even for the very heaviest water molecules, they're only going to have atomic weights of 22 vs. 18 with light water. And even then the heavy molecules are going to be rare, making for a very, very small difference.

The only real way to get around the limitation of the weight of water is to obtain water at the destination (or at some point inbetween).

Why would water be lighter than seperated hydrogen and oxygen (considering the same initial and final # of atoms)?

 

[KimB]

Why would water be lighter than seperated hydrogen and oxygen (considering the same initial and final # of atoms)?

Because mass = energy, and water is a lower-energy state. Granted, the difference will be so incredibly small that you'd have to devise an extremely clever experiment to measure the difference, but there will be some difference.

 

[AlphaWolf]

Only if you're doing so in an atmosphere, where buoyancy comes into play. But then the volume would probably be more of a hinderance than the weight.

Still, you have your terminology wrong: weight is the force of the gravity of the Earth on objects. Mass is something inherent about the object (it's the object's total energy). Water in gaseous form has every bit as much weight and mass as water in liquid form (actually, a tiny tiny bit more, as it's a higher-energy state).

Well I was actually suggesting you'd seperate the molecules into hydrogen and oxygen. I wasn't suggesting it would be a convenient form of transportation. Merely that it would be lighter. Maybe you could build a zeppelin to help with transport. Oh the humanity.

 

[droopy1592]

Because mass = energy, and water is a lower-energy state. Granted, it won't be much lighter (you'd probably have to devise an exceedingly clever experiment to measure it), but it will be somewhat lighter.

Energy state has more to do with stability in configuration and electron orbitals than mass loss due to oxidation (never heard of it). Can you show a link to provide more information. That confuses me. Electrons have a mass ridiculously lower than protons/neutrons and aren't really even factored into atomic weights. Electron numbers are still maintained after oxidation so where does the weight go?

 

[droopy1592]

Well I was actually suggesting you'd seperate the molecules into hydrogen and oxygen. I wasn't suggesting it would be a convenient form of transportation. Merely that it would be lighter. Maybe you could build a zeppelin to help with transport. Oh the humanity.

It still wouldn't be lighter. The H and O are going to weigh the same regardless. If you were to vaporize a liter of water or even seperate them into two different gases it would still weigh the same (assuming it is not mixed with other gases) it's just covering more volume and since it's density is much less it will now become bouyant. It still weighs the same, though. If you were to take a room full of Oxygen and reduce it's volume and temp both to near zero, the total weight of the gaseous oxygen and liquid oxygen would still be the same.

 

[FUDie]

Energy state has more to do with stability in configuration and electron orbitals than mass loss due to oxidation (never heard of it). Can you show a link to provide more information. That confuses me. Electrons have a mass ridiculously lower than protons/neutrons and aren't really even factored into atomic weights. Electron numbers are still maintained after oxidation so where does the weight go?

Chalnoth already explained that. The reaction of hydrogen and oxygen produces heat. Since heat is energy and E = mc^2, he claims are actually losing a small amount of mass.

However, I think he's wrong. The energy was already in the molecules on H2 and O2 and was released so no matter was destroyed. Matter is only destroyed in nuclear reations. This is the main difference between nuclear and chemical reactions.

-FUDie

 

[droopy1592]

Chalnoth already explained that. The reaction of hydrogen and oxygen produces heat. Since heat is energy and E = mc^2, he claims are actually losing a small amount of mass.

However, I think he's wrong. The energy was already in the molecules on H2 and O2 and was released so no matter was destroyed. Matter is only destroyed in nuclear reations. This is the main difference between nuclear and chemical reactions.

-FUDie

In an "excited" atom an electron has merely jumped an orbital into a less stable one. It hasn't gained any weight, the energy used to excite the atom is translated into "instability." If you excite a molecule and extract something to cause it to go into a less stable form, it will retain that energy until it stabilizes, but the increased energy level is not due to increased weight.

 

[AlphaWolf]

It still wouldn't be lighter. The H and O are going to weigh the same regardless. If you were to vaporize a liter of water or even seperate them into two different gases it would still weigh the same (assuming it is not mixed with other gases) it's just covering more volume and since it's density is much less it will now become bouyant. It still weighs the same, though. If you were to take a room full of Oxygen and reduce it's volume and temp both to near zero, the total weight of the gaseous oxygen and liquid oxygen would still be the same.

sigh.

I italicized lighter for a reason. I don't mean scientifically, I mean household transportability. In the same way that a hydrogen filled balloon is lighter than an empty balloon.

 

[FUDie]

In an "excited" atom an electron has merely jumped an orbital into a less stable one. It hasn't gained any weight, the energy used to excite the atom is translated into "instability." If you excite a molecule and extract something to cause it to go into a less stable form, it will retain that energy until it stabilizes, but the increased energy level is not due to increased weight.

I know all this, tell it to Chalnoth.

-FUDie

 

[KimB]

Energy state has more to do with stability in configuration and electron orbitals than mass loss due to oxidation (never heard of it). Can you show a link to provide more information. That confuses me. Electrons have a mass ridiculously lower than protons/neutrons and aren't really even factored into atomic weights. Electron numbers are still maintained after oxidation so where does the weight go?

All you need to consider is the fact that combining hydrogen and oxygen to make water results in an explosion. This means that energy was released, and thus by energy conservation water is a lower-energy state. And since mass is energy, the mass of the system will be ever so slightly less (yes, with the exact same number of protons, neutrons, and electrons).

 

[KimB]

In an "excited" atom an electron has merely jumped an orbital into a less stable one. It hasn't gained any weight, the energy used to excite the atom is translated into "instability." If you excite a molecule and extract something to cause it to go into a less stable form, it will retain that energy until it stabilizes, but the increased energy level is not due to increased weight.

Actually, it has. But the amount is very small.

Consider, for example, the hydrogen atom. If I remember correctly, the ground state of the Hydrogen atom is -14.6eV. The energy levels scale as 1/n^2, so the first excited state is -3.65eV. The difference in energy between the two, then, is about 11eV. Now, the mass of the hydrogen atom is approximately the mass of the proton, which I'll again approximate as 1GeV/c^2.

So, the hydrogen atom in the first excited state will be 11eV/c^2 more massive than a hydrogen atom in the ground state, which is roughly a 1/10^8 increase in mass (0.000001%).

This, to me, is a really interesting fact about how the world works. And it gets even more interesting when you look at Quantum Chromodynamics (the physics of quarks and gluons). When you examine the structure of the proton in detail, for instance, you find out that not only is it composed of quarks, but those quarks themselves have masses of only a few MeV. Since the proton's mass is nearly 1GeV, the majority of the mass in the proton comes from the binding energy (yes, it's positive: but it'd be more positive if the quarks were in any other state, so the proton remains stable).

 

[FUDie]

Actually, it has. But the amount is very small.

Consider, for example, the hydrogen atom. If I remember correctly, the ground state of the Hydrogen atom is -14.6eV. The energy levels scale as 1/n^2, so the first excited state is -3.65eV. The difference in energy between the two, then, is about 11eV. Now, the mass of the hydrogen atom is approximately the mass of the proton, which I'll again approximate as 1GeV/c^2.

So, the hydrogen atom in the first excited state will be 11eV/c^2 more massive than a hydrogen atom in the ground state, which is roughly a 1/10^8 increase in mass (0.000001%).

You've got something wrong. If the electron is at a higher energy state then it doesn't gain mass, it gains energy. If the energy is released, it doesn't lose mass, only energy. E = mc^2, but you only have one or the other at a time. Thus, if you've gained the energy, you don't gain the mass as well.

When two deuterium nuclei fuse to form a helium nucleus, the mass of the helium nucleus is less than the sum of the masses of the deuterium nuclei because some matter is converted to energy. This is not the case for chemical reactions however as matter is conserved.

-FUDie

 

[KimB]

You've got something wrong. If the electron is at a higher energy state then it doesn't gain mass, it gains energy. If the energy is released, it doesn't lose mass, only energy. E = mc^2, but you only have one or the other at a time. Thus, if you've gained the energy, you don't gain the mass as well.

No, you have both, at the same time. Energy is mass. That's what that equation says. It doesn't say you convert one into another. It's an equivalence.

What you're thinking of would be an equation written in the form:

E + mc^2 = const

...which gives the wrong sign in the relationship (the constant on the right isn't a problem: this just would redefine energy).

When two deuterium nuclei fuse to form a helium nucleus, the mass of the helium nucleus is less than the sum of the masses of the deuterium nuclei because some matter is converted to energy. This is not the case for chemical reactions however as matter is conserved.

This is no different from chemical reactions: only the force mediating the reaction is different. That and the change in mass is a much larger portion of the mass of the system. You're applying two different thought models to the different processes when, in reality, they're doing almost the exact same thing, just with a different force.

 

[KimB]

Thought I'd put an update in a separate post here.

Actually, a better way to think about it is not that energy is mass, but rather the other way around: mass is energy. Put simply, physicists working in high-energy theory typically believe that there are no particles that have inherent mass. Mass is always added to the particles via some sort of interaction. So the mass that we measure really is nothing more than the total energy in the system.

 

[FUDie]

No, you have both, at the same time. Energy is mass. That's what that equation says. It doesn't say you convert one into another. It's an equivalence.

Yes it's an equivalence, but you convert one into the other. Mass is potential energy until that mass is converted into energy. If your mass is 100 kg, that's not a lot of energy until you destroy the mass and release the energy.

What you're thinking of would be an equation written in the form:

E + mc^2 = const

...which gives the wrong sign in the relationship (the constant on the right isn't a problem: this just would redefine energy).

Not at all.

This is no different from chemical reactions: only the force mediating the reaction is different. That and the change in mass is a much larger portion of the mass of the system. You're applying two different thought models to the different processes when, in reality, they're doing almost the exact same thing, just with a different force.

Chemical reactions conserve mass. Please find me a source that says otherwise.

-FUDie

 

[Sxotty]

This has got to be more worthwhile that turning lead into gold right?

This topic is the most hilarious thing I have ever read I think.

You want to genetically engineer people so they don't need water? Or well whatever, you realize that we need a certain amount of water and it will always have the same mass. Are you really asking a question?

Sorry, but if youguys are talking about all this crazy crap, maybe you should just make water wherever you happen to be at the time from available hydrogen and oxugen...

 

[Ty]

Yes it's an equivalence, but you convert one into the other. Mass is potential energy until that mass is converted into energy. If your mass is 100 kg, that's not a lot of energy until you destroy the mass and release the energy.

Chemical reactions conserve mass. Please find me a source that says otherwise.

-FUDie

Given your two statements above, how do you remain consistent if a chemical reaction releases heat (energy).

That is, if you believe that:

Mass = Energy, and vice versa. And if a chemical reaction releases heat (energy) this would seem to contradict your second statement, that chemical reactions conserve mass simply because energy (or its equivalent, mass) was released.

Chalnoth is simply saying that an extremely tiny tiny amount of mass is lost due to water being at a lower energy state, which therefore means there is less mass.

 

[FUDie]

Given your two statements above, how do you remain consistent if a chemical reaction releases heat (energy).

That is, if you believe that:

Mass = Energy, and vice versa. And if a chemical reaction releases heat (energy) this would seem to contradict your second statement, that chemical reactions conserve mass simply because energy (or its equivalent, mass) was released.

Chalnoth is simply saying that an extremely tiny tiny amount of mass is lost due to water being at a lower energy state, which therefore means there is less mass.

Photons have no mass, yet they have energy. Q.E.D. It's a conversion. It's not trivial to convert mass into energy.

-FUDie

 

[DemoCoder]

The difference has been measured experimentally. Crack open your physics/chem book and they will tell you.