Handle objects that might be hot cautiously. Go to Top Disposal Heat the water in the flask to boiling to push the balloon from the flask. Remove the balloon while the water is hot. Discard the balloon with ordinary solid wastes. Go to Top Makeup Ans.
Water is boiled.
A balloon, which is placed over the hot flask, is sucked into the flask as the system cools. Water vapor produced by the boiling liquid fills the hot flask. The water vapor condenses to liquid which reduces the pressure in the flask.