- Introduction + question + presentation of the experiment.
- Expectations (I know the results) OR hypothesis regarding observations (I don’t know the results).
- Equipment and chemicals; safety instructions (e.g. dangerous material, disposal of waste).
- Practical implemantation/observations/explanations as a table.
- Evaluation: summary and generalization; hypothesis was correct or not + answering the questions.
- Errors: Are there results which are unclear or which you can’t use? Give opportunities to avoid those errors if repeating the experiment.
- Preview: Are there new questions? Think of new or further aspects to investigate.
All substances have specific characteristics, e.g. the aqueous solubility.
Can lighter fluid and sulphur be dissolved in water?
We put both substances in water to prove.
If sulphur and lighter fluid can be dissolved in water, then they won’t be seen in water.
If + guess, then + observation (+ justification).
If + observation, then + guess (+ justification).
- test tube stand
- two test tubes
- spatula
- sulphur
- lighter fluid (dangerous substance: flammable)
- water
disposal waste
– Filter off sulphur => could be used again
– Put lighter fluid and water in special vessel
| Practical implementation | Observation | Explanation |
|---|---|---|
| Put the sulphur in a test tube by using the spatula. Add water. | Before: During: After: |
|
| What am I doing with equipment and chemicals? | What am I observing? (only pecipience and measures) | Why? |
Sulphur can be seen on the surface of water. It has no aqueous solubility. Lighter fluid cannot be seen after water was added. It can be dissolved in water. The hypothesis is correct regarding the lighter fluid.
All substances have specific characteristics. There are some substances which can be dissolved in water and some which can be not.
It is possible to investigate more characteristics to describe the substance completely. Furthermore the solubility in other liquids (e.g alcohol) can be investigated.
