Water is put into a corked test tube at 25C. It is heated & the cork pops off. What must have been the min temp reached? Explain.
The question also asks to explain how you could measure this.
I'm having trouble understanding if this is about reaching boiling point or has something to do with critical temp.
So far, this is my reasoning: As temp rises, vapor pressure rises. The water would need to reach a temp of at least boiling point (100 C). At this temp, the vapor pressure of the water would be equal to the external pressure creating a equilibrium inside the tube. Any heat applied after reaching boiling point will increase the pressure inside the tube. The increasing pressure will eventually force the cork to pop and the highly energized water molecules to be released as steam.
I'm also at a loss for how this could be measured. A calorimeter came to mind, but that doesn't seem like it would work. All I can think of is just putting a thermometer inside the test tube and continually reading the temp until the cork pops off. Any suggestions?