Practical 10
The Different States of Water
Activity 1: What happens when water boils?
In this practical activity, you will first examine what happens when water boils, and then consider what happens when ice melts.
Apparatus
- Large beaker
- Bunsen burner with heat-proof mat
- Tripod and gauze
- Eye goggles
- Thermometer (optional)
Safety:
These safety points mainly tell you about hazard. You will need to think about the risk(s) this might pose, and how you can minimize the risk.
- The tripod stand and gauze may become very hot. Boiling water can cause burns.
- Take care when using Bunsen burners, and do not move Tripod stands until cool. Take care when using thermometers to avoid breakages.
- Glass thermometers may be fragile, and may contain mercury, which is toxic. If your thermometer breaks, tell your teacher immediately. Do not touch any broken glass or mercury.
- beaker
- water
- tripod and gauze
- Bunsen burner
- heat mat
Method
- Place a large beaker that is half-full of water on a tripod stand with gauze.
- Place a thermometer in the beaker.
- Place a Bunsen burner beneath the water, and light carefully.
- Write down the temperature every 5 minutes in the table below, and note down what you see happening in the water each time.
- Stop heating when the temperature approaches 100°C.
Results
Describe what you saw as the temperature of the water increases.
| Time (Minutes) | Temperature (°C) | What the Water Looks Like |
|---|---|---|
Discussion
- How long did it take for the temperature of the water to approach 100°C?
- What happened as the temperature of the water approached 100°C?
- Can you explain what you saw?
Activity 2: What happens when ice melts?
Apparatus
- Large beaker
- Ice cubes
- Thermometer
Optional: Bunsen burner, tripod, gauze, heatproof mat, eye protection
Safety:
These safety points mainly tell you about hazard. You will need to think about the risk(s) this might pose, and how you can minimize the risk.
- The tripod stand and gauze may become very hot – do not move until cool.
- Glass thermometers may be fragile, and may contain mercury, which is toxic. If your thermometer breaks, tell your teacher immediately. Do not touch any broken glass or mercury
- beaker
- ice
- water
Method
- Place some ice in a large beaker.
- Place a thermometer in the ice and record the temperature.
- Let the ice become heated, either using a Bunsen burner, or by placing the beaker in a warm place.
- Write down the temperature every 5 minutes in the table below, and note down what you see happening in the water each time.
- Stop recording when no more ice can be seen.
Results
Describe what you saw as the temperature of the ice increases.
| Time (Minutes) | Temperature (°C) | What the Ice Looks Like |
|---|---|---|
Discussion
- How long did it take for all ice to disappear?
- How could you describe the contents of the beaker at that point ?
- Can you explain what you saw?
Summary Points:
During this practical you have seen three different physical states of water.
- What are the three physical states of water?
- At what temperatures do these states change? What do we call these temperatures?
- What happens to particles of water when water is heated, and how does this explain the changes in states you have seen?