Aim: Exploring if it is a chemical or physical change.
Hypothesis: It's going to melt - Chemical change
Equipment:
- Sample of ZnO (Zinc Oxide)
- Heat source - Hot plate
- Scales
- Heatproof container - evaporating dish
- Tongs
- Heatproof mat
Method:
- Get a sample of ZnO (Zinc Oxide) in an evaporating dish
- Weigh the ZnO and container - record weight
- Heat container and ZnO on a hot plate
- Observe any changes - use a phone for before & after photos (could be video)
- Take off heat and put on a heat proof mat
- Let cool - observe - photos
- Re weigh
Results:
Before the experiment, we weighed the ZnO in a heat container, weighed 57g, then I put the ZnO and container on the hot plate. Then, I observed what changes occurred when the ZnO was heating up. After a few minutes, the ZnO slightly changed colour to a light yellow colour.
After the Zinc Oxide changed colour, I put the heat container on the heat proof mat and let it cool down. It took around 5 minutes to cool down.
After 5 minutes, we see that the Zinc Oxide's colour changed back to white which meant that it is a Physical change.
Conclusion
According to the results, my hypothesis was incorrect and it actually changed colour.
