Purpose
Visit six stations, decide whether each change is physical or chemical, and justify each decision with evidence.
Safety
Goggles the entire time. Station 4 uses dilute acid — rinse spills with plenty of water and tell me. Never lean over an open flame.
Disposal, and it differs by station. The precipitate from station 6 goes in the labelled waste jar, never the sink. Station 4’s contents are rinsed away with plenty of running water. Wax goes in the bin once it has set solid. Read this before you start, not when you have finished.
Stations
| # | What you do | Watch for |
|---|---|---|
| 1 | Dissolve salt in water | Does anything new appear? |
| 2 | Melt candle wax, let it resolidify | Is it still wax? |
| 3 | Mix baking soda and vinegar | Gas? Temperature? |
| 4 | Drop magnesium into dilute | Bubbles, warmth |
| 5 | Tear and crumple paper | Any new substance? |
| 6 | Mix lead-free solutions to form a precipitate | Solid from two clear liquids |
Data
| Station | Observations before | Observations after | Physical or chemical | Evidence |
|---|---|---|---|---|
| 1 | ||||
| 2 | ||||
| 3 | ||||
| 4 | ||||
| 5 | ||||
| 6 |
Analysis
- Which station was hardest to classify, and what would settle it?
- Station 3 gets colder; station 4 gets warmer. Both are chemical. What does temperature change tell you, and what does it not?
- In an open container, station 3 appears to lose mass. Explain using conservation of mass — see Physical and Chemical Changes.
Hand in
- Completed table with evidence for every row
- Analysis answers
Curriculum connection
A1.2
apply a scientific experimentation process and associated skills to conduct investigations, making connections between their observations and findings and the scientific concepts they are learning
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C2.1
investigate properties, changes, and interactions of matter that are important for the dynamic equilibrium of ecosystems and their sustainability
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A1.5
apply their knowledge and understanding of safe practices and procedures, including the Workplace Hazardous Materials Information System (WHMIS), while planning and carrying out hands-on investigations
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