1. Take a boiling tube having a cork with one hole.
2. Insert a thermometer into it.
3. Keep thermometer above water.
4. Start heating the boiling tube.
5. Note the temperature at which liquid water changes into vapours completely and temperature of thermometer becomes constant. It is the boiling point of water. Observe the temperature when the boiling of water takes place.
Conclusion: Water boils at 100°C or 373 K and the temperature remains constant till water changes into vapours completely.
