I was just thinking. Does water get created anymore? Or is the amount of water on the planet pretty much going to stay the same for the time being?
I mean on a molecular basis that is-- wether it be ice, water or in vapor form.
How hard is it to create water?
Oh man, any chemistry student has made water before. Basically all you need to do is get Oxygen and Hydrogen and get them to react with heat and you have water. The problem is that this is impossible to do on a large scale.
Much more complex exlpanation:
KE0103 Mikko Pennanen 02C
Water
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the liquid of life
Water is one of the most basic necessities of life. It covers 80% of the earth¡¦s surface, makes up 75% of a person¡¦s mass and up to 90% of the mass of plants. Plants need it for photosynthesis. People need it obviously to drink and also to bathe. The whole industrialized world is dependant on water. But what makes water special and vital? Hold on, you¡¦re about to find out.
A water molecule (H2O) consists of one oxygen (O) and two hydrogen (H) atoms. A water molecule is formed when hydrogen gets in contact with oxygen. Since oxygen atoms have six and hydrogen atoms have one electron on their outermost shell the easiest way for both to get an octet is to form a molecule with one oxygen and two hydrogen atoms. This happens the following way: oxygen, which has two single electrons on its outermost shell of electrons, and two hydrogen atoms, which both have one electron, join one another by giving one electron to a shared pair of electrons forming two covalent bonds.Water also has a structural feature that differentiates it from most other substances and makes it irreplaceable to life: it has hydrogen bonds. Hydrogen bonds formulate because oxygen is strongly electronegative (meaning it pulls the electron cloud near the nucleus) compared to hydrogen and because of that it pulls the shared electron pairs near itself. From this follows that oxygen gets a slight negative and the hydrogens get slight positive charges. Since opposite charges attract one another water molecules also attract each other, thus creating hydrogen bonds, bonds that not only make water a polar liquid but also make it so remarkable in the merry bunch of substances.
Hydrogen bonds cause water to have the following qualities. First of all the energy needed to break them in order to make water boil raises the boiling point of water by about 200„aC from -97„a it should be according to its elements to 100„aC. Hydrogen bonds also cause the surface tension. This happens because the molecules in the surface are only pulled by other molecules from below thus creating the ability to carry substances with higher density than the water itself. Subsequently hydrogen bonds cause the high distinctive temperature capacity of water, meaning it can bind a lot of warmth (or cold) to itself. And that¡¦s not all: hydrogen bonds also make water a good solvent. Water dissolves both polar and non-polar gases, all polar liquids and solid substances of both molecular and ionic structure. Dissolving ionic structured solid substance happens as follows: First water molecules subside around the crystal so that opposite charges of the ions in the crystal and in the water molecules are next to each other forming ionic-dipole bonds and, depending on if the salt is easily or hard dissolving, breaking it into negative and positive ions. Water molecules form a tight hydrate cloak around the negative and moore loose around the positive ions. If enough of the water from this kind of solution evaporates it first becomes saturated and then the salt solvated to it begins to crystallize taking part of the water molecules in the hydrate cloak with it into the crystal structure. This kind of chemically bond water is called crystal water and is marked with (aq) in a reaction equation. And MOREOVER because of the hydrogen bonds water gets three-dimensional hexagonal structure when it solificates (freezes) in 0„aC. A good thing to know about water is that it is an ampholyte, meaning it can act as both acid or base in acid-base reaction.
That is an awsome post. However, I meant to narrow my Question to nature. What happens in nature that changes the amount of water on the planet?
Well, the water on Venus was mostly lost by Photodissociation;
from here-
Loss of Water in Venus’s Atmosphere:
**1. An H2O molecule (present in atmosphere as water vapor) is broken down by UV sunlight.
2. The hydrogen atoms (light) are moving fast (because they are hot). If the velocity is high enough they escape to space.
3. The oxygen atom oxidizes surface minerals. **
The oxygen remains on Venus mostly in the form of CO2; the hyrogen is mostly gone for ever.
This is hardly happening at all on Earth, so we are not losing our water very quickly; we have a cool, thin upper atmosphere whereas Venus’s is thick and bathed in much stronger sunlight.
But in a billion or two years or so the Earth would lose all its water, as the Sun Heats up; eventually the Sun will become a red giant, but I expect the Earth will have been uninhabitable for a long time by then.
SF worldbuilding at
http://www.orionsarm.com/main.html
Run4YourLife: I guess you mean H2 + 1/2 O2 --> H2O; the experiment would be useful for verifying the calculated enthalpy of formation of water, but I don’t think it’s practical. I can only remember making water the boring way, NaOH + HCl --> H2O + NaCl… =)
The reaction you described is probably much better to conduct electrochemically. These are the half-reactions in a fuel cell:
Anode: 2 H2 --> 4 H+ + 4 e-
Cathode: O2 + 4 H+ --> 2 H2O
Overall: 2 H2 + O2 --> 2 H2O
Most of the water on Earth probably formed by this reaction, driven most likely by electrical activity rather than just heat. Some paleogeologists believe that the comets bombarding the Earth early in its existence may have provided much of the water also.
I can think of a few other ways that water can be added to or removed from the hydrologic cycle:
- By organisms. Organisms using O2 as the final electron acceptor in cellular respiration (everything except some bacteria) end up producing some water in that reaction. Many organisms use water as a source of hydrogen and oxygen in synthesizing organic molecules; plants require especially large amounts of water for making glucose from CO2 in photosynthesis.
- Volcanic activity, which forms sulfuric acid by a process that consumes water.
- By ultraviolet light. Ozone can be broken apart by ultraviolet light to form a species that reacts with water to give a molecule called the “hydroxyl radical”, which acts as a detergent in the atmosphere. Most hydroxyl radicals end up in reactions that yield water, so this doesn’t change much.
- By precipitation. The major reason why Earth doesn’t have much CO2 in its atmosphere is that, when it’s dissolved in water, it reacts easily with calcium to form calcium carbonate – limestone. At certain pH, water can react with different ions to give insoluble precipitates (e.g Al(OH3), but I’m not sure how significant this is.
- Combustion. When organic compounds burn, they release water vapor. (generally: x CaHbOc --> m CO2 + n H2O) Since humans like to burn things, we end up releasing a lot of water vapor into the atmosphere – far more than would have been released by fires before humans evolved. Water vapor is a greenhouse gas, and greenhouse gases lead to global warming, and global warming leads to more water vapor in the atmosphere, and so on…
I’m not sure how significant each of these are. I would think that the most important source of water outside the hydrologic cycle is combustion of organic matter. The most important sink (the opposite of a source) would likely be the incorporation of water into organic molecules, mostly by plants and other photosynthetic organisms.
Since we are not being bombarded by comets at this moment in our history, and we are not losing much water to space by photodissociation, the amount of water on Earth remains more or less the same over time.
The Hydrological cycle only removes water temporarily- even the waterthat is lost by subduction into the Eart’hs crust will resurface via volcanoes-
actually, there is no guarantee that geological cycles are always evenly balanced- for more than a billion years, more carbon has entered the crust than left it, so we are gradually running out of CO2.
More important for the survival of the Human species is the balance of salt waterto fresh- much of the world is deficient in fresh water, and places were it is abundant, like Antarctica and Canada, are cold and the water is often present as ice.
To obtain fresh water for agriculture in many parts of the world expensive energy is required.
Thankyou, those are the types of answers I was looking for, especially this one;
"During the Hydrologic Cycle, the earth’s water is cleansed – it is not created or destroyed. Simply put, the water is continually changing location and form. The water you drink today may have been lapped up by dinosaurs millions of years ago, or used to fill Julius Caesar’s bathing pool. The water we use now is the same supply the human race started with. Its quality is renewed again and again by the natural Hydrologic Cycle "
And Roches post too.
eburacum brings up a good point too, are the prosesses evenly producing and removing water molecules from the Earth or not. And how much is broken down or produced by organisms, and natural chemical reaction.
Forgot to add;
Are there any natural prosesses that consistently remove or add water to the supply?
Wow. That cite on the hydrologic cycle is just plain wrong.
The respiration-photosynthesis is
6CO2 + 12H2O <—> C6H12O6 + 6O2 + 6H2O
So basically, with every breath you take, you destroy and create new water molecules. They are not simply passed through as the same molecule, as if they were they wouldn’t show up. I honestly can’t remember the full Creb’s cycle anymore (heck, I can’t even remember if it’s spelled with a C or a K 
), but yes, individual water molecules are constantly being made and broken in plants and animals. Not in evaporation and rain, though, those will be the same molecules being moved around.
As for natural processes that consistently change the supply, probably not today, so much. Basically, when plants first evolved, there was no oxygen around, so the early plants (or aerobic microbes to be picky) used up a net of 2 water molecules for each oxygen in the atmosphere today. That process kinda stabilised, though, when the biomass (carbon) and atmospheric oxygen pools did.
Then there was a period of a few million years where a bunch of biomass got sequestered into the ground as fossil fuels. That would also have used up water, on average.
Now, we’re taking some of that biomass out of the ground, and putting it back into the atmosphere and biosphere. This will also release some of the water stored those millions of years ago. But you may not consider this a natural process.
Of course, it’s possible that biomass is still being accumulated and sequestered in peat bogs somewhere; this would also remove water from circulation.
Concerning hydrogen burning with oxygen:
OF COURSE
Concerning hydrogen burning with oxygen:
OF COURSE it forms water. Water is incredibly stable. Hardly anything reacts with it. This is why pure water doesn’t go bad (mostly). If it’s not going to form water, what do you propose that it does form?