How to write a report?
- 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.
Introduction + question + presentation
All substances have specific characteristics, e.g. the aqueous solubility.
Lighter fluid and sulphur can be dissolved in water?
We give both substances in water to prove.
Hypothesis
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).
Equipment and chemicals
- test tube stand
- two test tubes
- spatula
- sulphur
- lighter fluid (dangerous substance: flammable)
- water
disposal waste
– filter off sulphur => could be used again
– give lighter fluid and water in special vessel
Practical implementation/observation/explanation
| Practical implementation | Observation | Explanation |
|---|---|---|
| Give 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? |
Evaluation
Summary + hypothesis
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.
Generalization
All substances have specific characteristics. There are some substances which can be dissolved in water and some which can be not.
Preview
It is possible to investigate more characteristics to describe the substance completely. Furthermore the solubility in other liquids (e.g alcohol) can be investigated.