Hydrogen Bonding

[HydrogenBond]

When O2 and H2 react, this highly exothermic reaction will produce water. The oxygen will gain electron density from hydrogen to form a more stable octet of electrons; in doing so the oxygen will become anionic. This should be exothermic. The hydrogen, on the other hand, loses some electron density with respect to H2 to become slightly positive. This should be endothermic since the hydrogen will lose orbital stability. The question is, does the hydrogen of water carry the burden of potential with respect to the formation of hydrogen bonds?

[HydrogenBond]

I am trying to deduce this with logic. Oxygen often exists as oxide or O-2. Oxide has two more electrons than nuclear protons. This disproportionate charge can not be explained with electrostatic attraction alone. What is also also required is magnetic addition to overcome the electrostatic repulsion. Within molecular water the oxygen is not quite able to form the oxide state. It can only go so far, due to the potential that is created within the hydrogen. The hydrogen has its own EM needs. To remove its induced potential hydrogen seeks electron density from water to form a H-bond. The oxygen by losing electron density is pulled farther away from oxide. Its charge may be better stabilized but it lost some magnetic addition to the hydrogen. Oxygen will take the induced potential out on its own hydrogen further increasing its potential.

 

The freezing of water causes the water to expand instead of contract. This appears to reflect the optimized electrophilic needs of both oxygen and hydrogen. If it was pure electrostatic or ionic, water should contract like any other polar material. Within liquid water, the h-bonds get closer due to the oxygen twisitng away from the hydrogen. This shifts the opimitize linear h-bond angle requiring closer hydrogen approach to lower its potential. In a pure electrostatic/ionic bond, the extra heat within the liquid phase should separate the ions rather than bring things in closer.

 

One last observation about the electrophilic potential of water is connected to the oxidation of metals. If we place almost any metal within water, it will oxidize. The hydrogen acts as a catalyse, while the oxygen is able to form its stable oxide state.

[UncleAl]

Illucid.

[Jay-qu]

Illucid.

 

thats so not a real word...

[UncleAl]

Illucid and willfully ineducable.

[CraigD]

I am trying to deduce this with logic. Oxygen often exists as oxide or O-2. Oxide has two more electrons than nuclear protons.

My understanding of chemical nomenclature is rudimentary, but my every-faithful internet encyclopedae tell me that “oxide” is just a term used in combination with a number prefix to describe some number of oxygen atoms in a compound with other elements, eg: “carbon monoxide”. I’ve always heard molecules of O2 called “oh two” or just “oxygen”. I’ve never before encountered the claim that O2 normally exists with other than the usual 16 nuclear protons and 16 orbital electrons.

 

PS: It’s curious. For as long as I can remember, I’ve heard, understood, and used the word “illucid” to mean “not lucid”. It’s one of UncleAl’s favorites. Yet, when I check a popular reference like http://thesaurus.reference.com/search?q=lucid, it supports Jay-qu’s claim that it’s not a “real” word!

 

“Lucid” derives from Latin, so should have antonym “illucid”, yet the latter word seems to have somehow fallen off the English borrow word express.

[Jay-qu]

PS: It’s curious. For as long as I can remember, I’ve heard, understood, and used the word “illucid” to mean “not lucid”. It’s one of UncleAl’s favorites. Yet, when I check a popular reference like http://thesaurus.reference.com/search?q=lucid, it supports HydrogenBond’s claim that it’s not a “real” word!

 

Jay-qu... :hihi:

 

yeah I searched google, dictionary.com and my big fat maquarie dictionary and I couldnt find it, but I see what you mean by it been the antonym of lucid, it makes sense...

[HydrogenBond]

Here is another way to look at it. The formation of the -OH bond has a higher bond energy than the H-H bond energy, which is part of the reason the formation of water is higher exothermic. If we look at atoms instead of bonds, the H had less potential within the H-H bond than the -OH bond, since only a slight van der Waals potential existed within H-H. Whereas the potential of H increases into another classification within -OH bond called hydrogen bonding potential. The O as O2 lowers its potential when a -OH bond forms due it being able to better complete its outer octet of electrons becuase it is delocatizing more electron density from a less electronegative atom. The stability of the -OH bond is exothermic to the O atom but endothermic with respect to the H since the H has more residual potential than it started with.

 

When a hydrogen bond forms the H lowers potential by sharing the unbonded electrons of O. But the O loses some magnetic addtions for its remaining electrons; it is pulled a little bit away from the octet stability. The O may lower charge potential by the electron delocatization but gains some magnetic potential with respect to its octet stability. The hydrogen gains two-fold, while the oxygen gains one-fold.

[HydrogenBond]

I finally figured out a way to explain my intuition about H bonding. An easier example to see is HCl. When HCl is dissolved in water the Cl- is a very weak base due to the high electronegativity of the Cl. The H forms the acid part of hydrochloric acid. The H of HCl has a greater electrophilic potential in proportion to the nucleoplilic potential of the Cl due the high electronegativity of the Cl. Water should also be similar due to the high electronegativity of oxygen. The hydrogen will have a higher electrophilic potential in proportion to the nuclephilic potential of the oxygen due to the higher electronegativity of the O. This causes H to carry the primary burden of potential going into a H-bond.

What do you think UncleAL?