1. The problem statement, all variables and given/known data I need to explain what happened here... My teacher boiled water in a flask using a bunsen burner. Then he stoppered the flask and turned it upside down and boiled the water using ice. 2. Relevant equations • Boyle’s Law is the principle that at a constant temperature the volume of a confined ideal gas varies inversely with its pressure. • Boiling - A liquid boils at a temperature at which its vapor pressure is equal to the pressure of the gas above it. The lower the pressure of a gas above a liquid, the lower the temperature at which the liquid will boil. 3. The attempt at a solution So I looked it up, and I don't quite understand it. Heres a website that explained it (http://www.newton.dep.anl.gov/askasci/chem00/chem00894.htm). What I don't get is why the pressure dropped inside the flask?