Physical or Chemical Change (heating ZnO)

Hypothesis: I theorize that the change will be physical, it will have heat but will remain as a physical change.

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Equipment: 

• Sample of ZnO (Zinc Oxide)
• Heat source - Hot plate
• Scales
• Heat proof container - Evaporating dish
• Tongs
• Heat proof change

 

Method:

1. Get sample of ZnO in an evaporating dish.
2. Weigh the ZnO + container - record the weight.
3. heat container + ZnO on hot plate.
4. Observe any changes - use phone for before + after photos (video?)
5. Take off heat + put on heat proof mat.
6. Let cool - observe - photos
7. Re-weigh

Results: What? - Write your description

When the ZnO was heated, initially there wasn't a visible change. However after a few minutes there were signs of change by means of colour. The white powder began to change into a pinkish colour into which after a few moments more changed into yellow. When the compound was weighted before putting it in the heat, with the dish it weighed 57g (ZnO solely was 2g) which was the same as when the experiment was over. After cooling the compound changed back to its initial colour.

Conclusion: Explain the results - connect to the Hypothesis

In conclusion to the experiment the  Hypothesis that I have theorised was indeed correct. Although the change of colour was indeed a sign of chemical change, there were other factors into which point onto the other option. Examples of physical changes that it showed are as follows; weight was the same, it was "reversible" per se, as it reverted to the original colour and finally, no other compound was created during teh process.