A Water Molecule's Chemical Formula Isn't Really H20

hackwrench writes "According to this article in Physics News Update, a water molecule's chemical formula is really not H2O, at least from the perspective of neutrons and electrons interacting with the molecule for only attoseconds (less than 10-15 seconds). According to new and recent experiments, neutrons and electrons colliding with water for just attoseconds will see a ratio of hydrogen to oxygen of roughly 1.5 to 1, so a more accurate formula for water under these circumstances would be H1.5O."

Comments

Question.

[sporty]

Isn't H1.5O illegal nomenclature? Shouldn't it be 2H30? Mabe cp30?

Re:Question.

[Sgt York]

2H3O? H3O2? H6O3.1416?

That's what you get when two fields collide like this. H2O is a stoichiometric formula, it's not supposed to represent the actual molecule at all times. If the ratio for water was actually 3:2 instead of 2:1, fuel cells (like on US space missions) would wind up with an excess of hydrogen after reaction. That has not been observed. Also, if you electrolyze water, you get a 2:1 molar ratio of H to O. Not a 3:2 ratio.

If yu take pure water, you will not find a homogeneous mixture of molecules consisting of 1 oxygen bound to 2 hydrogens. You will find mostly that, plus OH, H3O, and free protons (H+). Th stoichiometry, however, still works out. There are 2 hydrogens for every oxygen.

Lower interaction rate, not fewer atoms.

[Christopher Thomas]

The spin in the article is misleading. What's actually happening is that the interaction cross-section between electron and neutron beams and the hydrogen in water (and in things like hexane) is lower than expected relative to the interaction cross-section with oxygen or carbon.

The conjecture about why the phenomenon occurs (entanglement of protons) is interesting, but they're going to need to find a plausible mechanism and confirm that it's happening before we really know what's going on.

Re:Can you say WRONG

[OwnerOfWhinyCat]

Must agree Markus. The cow leg counter is a great example.

The absurdity in the article makes one wonder where we've been getting all that hydrogen from for all these years. We've been cracking H2O with electrolysis and been getting both H's pretty consistently for decades. The experiments that show the PH are pretty solid as well, so it seems a little early to start theorizing that black holes are giving off the extra half a mole of Hydrogen we've been getting out of a mole of water.

The cool part (that they seemed to entirely miss) is that these techniques could be used to confirm/reject models for wave-theory covalent bonding. Maybe that tough little benzene ring is resonant at more than just the electron shell level....

Wish there was more detail on the experiment

[jgoemat]

This does not mean that water molecules have one and a half hydrogen atoms at all. If you use electrolysis to separate the hydrogen and oxygen from a quantity of water, you will get VERY close to twice the number of oxygen atoms as hydrogen. If they gave a little more detail on their experiments it would be helpful to judge what they actually mean.

For instance, if they are just shooting electrons and neutrons at water and counting how many hit hydrogen nuclei and how many hit oxygen nuclei, you would expect a larger number than normal to hit oxygen since the nucleus is larger (three times the protons and neutrons of hydrogen). They do say "25% fewer protons than expected", but they don't say what they expected or why.

Also, did they have the water in a vacuum chamber? If not, there would be dissolved gasses present in the water that their beam could hit as well. I didn't notice any count for Nitrogen so they must not have done it in a glass sitting on a table, but they don't say.

Re:More than elementary chemistry

[MarkusQ]

Meaning that if the water has a pH of 7 then we should be expecting something closer H1.999O.

No, we should expect to find a mix of H2O, H, and OH. In any macroscopic volume the ratio between H & O should be 2, not 1.999 or even 1.9999999. The pH shouldn't even enter into it (if the H+'s collectively wandered a macroscopic distance from the OH-'s, water would be incredibly dangerous).

Remember, they were looking at the H's & O's via p + n & p + e scattering.

-- MarkusQ

Too fast?

[Mark of THE CITY]

If the interaction lasts 10^-18 s, then by special relativity the neutron couldn't interact with anything more than 0.3 nanometer away, or 3 angstrom. Any chance that the experiment is too fast to see the surroundings?

Re:water in time

[macemoneta]

> And if it was H2O.99999973 , we'd know what CPU they used to count it with....

This was a funny, but it's also very true. People forget that the instrumentation used is also subject to error. I once spent a day hunting down a network problem, only to realize that the test equipment was creating the error, not the equipment under test. All the same model equipment from that manufacturer had the flaw, which we proved with test equipment from two other manufacturers.