Lesson Plans: Thermal Expansion of Water
Objective
The objective of this activity is to demonstrate the concept of thermal expansion of water when heated.
Materials
Each student or group of students will need the following:
- 500-milliliter conical flask
- Two-hole stopper
- Hollow glass tube
- Thermometer
- Ruler
- Stand with gauze mat
- Bunsen burner
- Graph paper
Important Points to Understand
- Global temperature is gradually rising according to the long-term temperature records.
- Solid, liquid, or gas in any shape may expand because of heat.
- If this heat from global temperature rise is passed on to the water, water expands and increases it volume.
Preparation
Before the demonstration, try to explain about the volume and volume expansion due to heat by giving some practical examples.
Then, explain when global warming heats up the upper layers of the ocean, the volume of sea water expands. It is this thermal expansion of the ocean water which makes the sea level rise.
Recently, it was asked why a bunsen burner was heating the Erlenmeyer flask in this experiment, see the answer.
Procedure
- Fill the flask to the top with water. Place the hollow glass tube and thermometer in the stopper and gently press the stopper into the flask.
- Mount the ruler so that the water level in the glass tube can be measured.
- Heat the water slowly and record the water level at 2-degree Celsius intervals. Record the temperature and water level at least ten times.
- Plot your results on a graph paper: temperature versus water level (volume expansion).
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | |
| Temperature (degrees Celsius) | ||||||||||
| Water Level (mm) |
