demonstrations:hot_water_condensation
Hot Water Condensation
Materials: ★☆☆ Easy to get from supermarket or hardware store
Difficulty: ★☆☆ Can be easily done by most teenagers
Safety: ★★☆ Some safety precautions required to perform safely
Categories: Particles and States of Matter, Water Cycle
Alternative titles: Water Cycle Condensation
Summary
This experiment demonstrates condensation, a key stage in the water cycle. By placing an upside-down cup with an ice cube over a cup of hot water, students can observe how water vapor cools and condenses into liquid droplets, similar to how clouds form in the atmosphere.
Procedure
- Boil water and carefully pour it into a transparent plastic cup until it is two-thirds full.
- Place a second cup upside down over the hot water cup.
- Balance an ice cube on top of the inverted cup.
- Watch closely as condensation forms inside the upper cup.
- Observe how small droplets gradually combine into larger ones, mimicking how clouds form.
Links
Condensation Experiment | The Water Cycle - Hannah Leake:
Variations
- Try using multiple ice cubes to see if condensation increases.
- Test with warm water instead of hot to compare how quickly condensation occurs.
Safety Precautions
- Handle boiling water carefully to avoid burns.
- Adult supervision required for younger students.
- Ensure the cup with hot water is stable to prevent spills.
- Be cautious when balancing the ice cube to prevent slipping accidents.
Questions to Consider
- Why does condensation form inside the second cup? (Because water vapor from the hot water cools against the cold surface, turning back into liquid droplets.)
- How is this similar to cloud formation? (Clouds form when warm, moist air rises, cools, and condenses into water droplets.)
- What would happen if you used cold water instead of hot? (Much less vapor would form, so condensation would be minimal or absent.)
- Why do the small droplets eventually merge into larger ones? (Water molecules attract each other, causing droplets to coalesce.)