Edit: wow okay, I did not expect to wake up to THIS. Of course my most popular post would be a dumb stoner question.
Thankyou so much for the awards and the answers, I can sleep a little easier now
In: Chemistry
We do make water like that, as a number of other commenters have said. In fact, there’s a very specific application where we want to make water exactly like that: [in a rocket engine](https://en.wikipedia.org/wiki/Liquid_rocket_propellant#Hydrogen). Because the act of combining oxygen and hydrogen to make water is very energetic and releases a lot of heat, and because water is actually quite a light molecule and all that heat makes it easy to accelerate it, rocket engines using hydrogen and oxygen are amongst the most efficient. The most well-known examples of a ‘hydrolox’ engine are the [Space Shuttle main engines](https://en.wikipedia.org/wiki/RS-25).
The simple answer is that when you try to smoosh them, they bounce off each other.
Why? Well, the hydrogen and oxygen you normally find lying around are already combined happily with themselves, into their own molecules (H2, meaning 2 hydrogens combined together; or O2 which means the same thing for oxygen).
They are each so happy about this state of affairs that even if you squished them really hard they wouldn’t want to give it up and combine together to form water. The molecules literally just bounce against each other even harder, which you as a human (rather than a molecule) would see as the temperature of your oxygen-hydrogen mixture rising the more you squished.
However. That does not go on forever. If it gets hot enough, or high enough pressure, or some combination of the two, then all the bouncing around *will* start to break the molecules apart, and once they start to break apart, then you’re in business. (Assuming your business is making water out of hydrogen and oxygen, and also releasing *a lot* more heat, because that is what will happen next.)
So, in a sense, you can, indeed, make water by smooshing hydrogen and oxygen together. You just have to smoosh *much much* *harder* than you are probably thinking of. And at that point it might just be simpler to emit a little spark of electricity instead to trigger the whole thing, which is what people normally do.
Also, for a fun trick, in the presence of powdered platinum, hydrogen and oxygen become much more willing to break out of their existing situation and combine with each other instead. In fact hydrogen and oxygen are so into it that they will do so at the kind of temperature and atmospheric pressure that you are used to living in every day, provided that you have the powdered platinum handy. No spark required, no heat required, they just combine right then and there! Rather explosively! So in another sense, you don’t even have to do *any* smooshing — they will just do it if platinum is there to make the introduction!
Sure we can. It’s just we don’t normally have access to H or O atoms, as under standard conditions they occur as diatomic molecules: H2 and O2. You’d need to break these bonds first, which would require smooshing them at rather high velocities.
Oxygen is easy to come by, getting free hydrogen is the real trick, because it wants to bond with something. Hydrogen is everywhere, but it’s usually bound to other elements in the form of compounds.
There are tons of compounds that contain hydrogen. If you combine them with a reactant or catalyst, some of them will yield free hydrogen. The real trick is finding a compound that doesn’t produce a toxic byproduct. You might get free hydrogen gas, but what’s left might be very volatile or toxic. There are other problems as well. The reaction itself could be explosive, or require so much energy to separate the hydrogen than it’s just not efficient.
To make water, you need oxygen, hydrogen and heat in a confined space. Once you have the free hydrogen, the hard part is done. You get the heat by igniting the hydrogen. Last problem to consider is burning the hydrogen in a slow controlled manner. Too much hydrogen and it’s not a slow burn, it’s an explosion.
If you watch The Martian, he used an iridium catalyst to separate the hydrogen and nitrogen from hydrazine (rocket fuel).
We CAN.
Now, it’s not very often in nature you come across pure hydrogen and pure oxygen. But if you do have pure hydrogen and pure oxygen and you put them together in the right ratio, it’s very easy to get them to form water. In fact, it’s hard to PREVENT them from forming water.
It’s a common 9th grade science experiment, you run electricity through water in a certain way and one electrode has bubbles of pure oxygen forming on it and the other pure hydrogen. You catch each in their own test-tube. You combine the two. A very small spark will cause them to smoosh together and form water. Thing is, sometimes you don’t even need a spark, sometimes just the right (or wrong) type of shaking will do the trick.
Now, in the process of forming water a lot of heat is generated, which has the potential to be very damaging.
Also, pure oxygen tends to burn super easy so there’s not a lot of pure oxygen around. And pure hydrogen tends to react with stuff a lot too. So you don’t bump into pure forms of them very often in nature. And making pure forms of them is relatively difficult and expensive.
**DUE TO REQUESTS – VIDEOS**
[https://www.youtube.com/watch?v=38ULHoKWZag](https://www.youtube.com/watch?v=38ULHoKWZag) – an animation of what is going on
[https://www.youtube.com/watch?v=9j8gE4oZ9FQ](https://www.youtube.com/watch?v=9j8gE4oZ9FQ) – a guy using 2 thumbtacks and a 9 volt battery to do this – but he isn’t catching the gas
[https://www.youtube.com/watch?v=UV8KbQyF228](https://www.youtube.com/watch?v=UV8KbQyF228) – a guy mixing O and H in front of a flame, it goes POP and they zoom in on the small droplets of water formed on the inside.
[https://www.youtube.com/watch?v=gZJEDe_HUcw](https://www.youtube.com/watch?v=gZJEDe_HUcw) – a guy builds a medium simple electrolysis set, then fills plastic bags with Oxygen and Hydrogen – then lets them float around.
[https://www.youtube.com/watch?v=vFR9zUGt2C4](https://www.youtube.com/watch?v=vFR9zUGt2C4) – a very classic ‘9th grade science’ experiment version
**Wow, this question has received a TON of awards – gold, silver, hugs, wholesome, heck some guy sent me some art. I am amazed, this is very unexpected, I was just trying to be helpful.**
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