I have a doubt about heating a liquid in a closed container. Firstly, we need to say a liquid boil when its vapor pressure equals external pressure. If we heat a liquid in a closed container, no boiling will occur. It's impossible to realize total vacuum so the pressure in the container is always bigger than the vapor pressure because the pressure in the container is the sum of the pressure of the initial air pressure and the vapor pressure. This should be right. But what if we consider total vacuum is possible? In this case the pressure in the container (the "external pressure") would be the vapor pressur itself and the boiling must occur. Is it right?
I hope my English wasn't so bad