I understand the basic connections between vapor pressure of substances and how this effects their boiling points. However, I am a bit hazy on applying it to some real life situations so I want to give some examples to check where I might be going wrong in my thinking. 1. I have 70F water in a beaker. I put it into a tube where the pressure is at 0.739 in.Hg so the water is boiling and has a temperature/pressure relationship. I now reduce the pressure in the tube so it is at .180 in Hg corresponding to the boiling point of 32F of water. Since the pressure in the tube is reduced, what changes here? I mean, the water temperature of 70F is well over 32F so the water would still be boiling so would this just all change to vapor or would the temperature decrease? I am also confused as to what point the boiling would stop if a decrease occurs. 2. Let's say I have a superheated vapor of water where the absolute pressure is .180 in.Hg and the temperature is let's say 40F (so 8 degrees F above boiling point). The vapor then goes through a .180 in.Hg tube and into a piston which compresses and decreases the volume of the vapor. Since the molecules are being compressed, they increase in their KE which results in an increase in their pressure and an increase in temperature of the superheated vapor as a result correct? Thus, if they exited in a different tube, the pressure/temperature would be higher but it would still remain as a superheated vapor. 3. I have a subcooled liquid where the temperature/pressure relationship is 125F/278 psig for a substance so the substance is a liquid-vapor mixture. I now take away some thermal energy so the liquid-vapor mixture becomes a subcooled liquid. The subcooled liquid now immediately is forced into another tube where the pressure is 69 psig. The temperature/pressure relationship is 69 psig/-41F. In terms of pressure/temperature relationship, since the temperature of the subcooled liquid is 110F and is above the boiling point of -41F, the liquid should start boiling. However, I also know that in general, reducing the pressure will result in molecules moving slower. Thus, I am having issues connecting these concepts in this context. In any case, if the subcooled liquid boils, how much is it boiling? Does it boil to -41.0F and then stop since this is at equilibrium?