>>11939345You literally posted a phase diagram. You should be able to very quickly work out what will happen.
Pick a point in the liquid domain. Any point. Trace a line to the right, ie heat the substance, such that it crosses the boundary, or vaporizes, into a gas. Then trace a line directly upward, ie compress the substance, then trace a line directly left, ie cool the compressed substance back to the same temperature that you started.
What matters most is the length of the lines - how much you are heating and cooling and compressing the substance. In some cases, you can start with a liquid, heat it until it vaporizes, compress it, and then cool it leading back to a liquid. If you start near the triple point, heat it to a gas, compress it to a very high pressure, and then cool it, you'll end up going from liquid to gas to higher pressure liquid to solid.
So your original question can't be answered without specifying *how much* you are heating and compressing the substance. But by understanding the phase diagram, you can see what would happen.
The phase diagram is also a good way to demonstrate why it's not correct to say that you "can't compress liquid." You absolutely can. There's lots of points in the liquid domain where you can increase pressure and still have a liquid.
