After water is boiled in a sealed flask, the flask is inverted and ice is placed on its base. The cooling reduces the pressure inside, causing the water to boil again at a lower temperature.

1. Fill a flat-bottomed glass flask with water and bring it to a boil using a hot plate.
2. Remove the flask from the heat and immediately seal it with a bung.
3. Allow the flask to cool slightly for about a minute.
4. Invert the flask and secure it on a ring stand.
5. Place ice cubes on the flat bottom of the flask.
6. Observe as the water begins to boil again, despite cooling.

Boiling Water Using Ice - mrsciguy:

Boiling Water with Ice - Pueblo Science:

📄 Boiling Water with Ice - MettLink: https://www.metlink.org/experiment/boiling-water-with-ice/

• Try the experiment at different starting water volumes to compare boiling intensity.
• Relate the experiment to high-altitude cooking by simulating different pressure conditions.

• Use heatproof gloves when handling hot glassware.
• Ensure the flask is borosilicate glass to withstand thermal stress.
• Perform the experiment on a heatproof mat.
• Handle boiling water carefully to avoid burns.
• Do not continue boiling the water once the flak has been stoppered.

• Why does the water start boiling again when ice is applied? (The cooling reduces internal pressure, lowering the boiling point of water.)
• How does this experiment relate to atmospheric pressure? (At higher altitudes, lower air pressure lowers the boiling point of water, just like in the flask.)
• Why is it difficult to brew tea properly on Mount Everest? (At 330 mb, water boils at about 70°C, too cool to extract flavor effectively.)
• What real-world systems rely on pressure to change boiling points? (Vacuum distillation, refrigeration, and pressure cookers.)