Would it just turn into a pressurized container full of steam? Would the water stay water but just like, really hot?
In: 98
Yes and no; depends entirely on your scale and perspective.
Let’s consult the [phase diagram of water](https://fi.m.wikipedia.org/wiki/Tiedosto:Phase_diagram_of_water.svg). From this we can see depending on the pressure water can have many forms. In near vacuum water will turn to vapour even in -50 Celsius. This curious effect is why north and south poles are actually the driest places, along with Atacama Desert, on earth.
But lets focus on your example. Let us say that we start with a container at one bar just above 0 so the water remains liquid. As we start to heat it up, the water temperature increases. Which means the molecules have more kinetic energy and they collide more with the walls of the container – this means that the pressure increases. It is important to understand what *heat* actually is, it is movement in a defined volume. When materials transfer heat between each other they actually collide and energy is transferred. Same amount of movement – as in energy – compressed in to smaller space means that things get hotter, alternatively same amount energy expanded to a greater space means things are colder. Hot and cold here being rather irrelevant concepts, it is just energy in a volume of matter. Now as things have more energy they collide more often and with more force; which in turn means more pressure and more transfer of heat.
So this all simple as long as we stay in the realm of daily physics, but deep in the earth’s crust, on the surface of other planets and inside starts things get weird really quickly. But lets start close to the ground or rather in the ground, which is also where chemists and physicists who like to play with really high pressures, temperatures and energies like to have their labs incase of a rapid unplanned disassembly occuring.
If you look at the phase diagram I linked you might see that it doesn’t really keep for that long, ending at 647,094 Kelvin and mere 22,064 MPa. So whats beyond that? Well there we get in to the weird territory of supercriticality.
What is supercritical you may ask? Well imagine something is at the same time both liquid and gas. This should be easy, right? At 0 Celcius we can have ice, water and vapour! What’s the big deal? Well like I said things get strange when ever *critical* is applied to it. Supercritical water has funky property of simply not caring about limitations imposed to it as liquid or as gas, it has the benefits of both without the downsides. It can flow like water, and it can go through things like a gas. This is because at some point, water has so much energy that it simply doesn’t care and does what it wants. It’ll go through solid matter… well *solid matter*, if you ask Hydrogen then anything that is solid is more or less a speed bump than a barrier. What I mean to say, if you ram your car fast enough to a wall, you’ll go through it. Regardless how strong the wall is, your car can go through if you add enough energy to it. It might not be a car at that point, but what is car but a collection of molecules arranged in a particular way.
Right… So what happens if we can keep the water contained still. Prevent it from escaping IN TO the walls of our container. Well if you heat up even more, soon the water will break down to hydrogen and oxygen as both of them have different properties and given enough energy they’ll just go do their own things for a while.
So the molecule has broken down to it’s parts. While we are at it like we Finns like to say: “*Ei tunnu missään, löylyä lissää!*” – *Doesn’t feel like anything, add more steam!* So lets do that. Keep increasing the heat, we have come this far an our apparatus have yet to do a ventilation hole to the ceiling of the lab. As we add more energy the gasses become plasma, as in the electrons realise that they are strong independent particles who need no nuclei, and decide to go look for who they really are before permanently settling down again.
But we ain’t done yet! We can go even further! Dad ain’t home so lets give the thermostat a spin like we are playing wheel of fortune. As we add more energy, and pressure goes up, the fundamental particles start to break down to quark and gluons. And after that no matter how much energy you add, that is where things stop. You have reached the state of matter universe right after the big bang.
Latest Answers