Chemical & Physical Changes Lab Review Copy these on your own sheet of paper you’ll need this for your conclusion

Station 1: Mixing Salt and Water Type of Change: Here’s Why: Physical NaCl breaks apart into Na+ and Cl- ions, which become uniformly distributed

Station 2: None

Station 3: Sugar, Water, and Yeast Chemical Type of Change: Here’s Why: The warm water made the yeast 'wake up' and it immediately started to have a chemical reaction with thesugar. Two substances, yeast and sugar, reacted to each other and together they made a new substance – a gas called carbon dioxide plus alcohol.

Station 4: Styrofoam + Acetone Type of Change: Here’s Why: Physical Styrofoam is mostly air, so adding it to acetone causes the air to be released and the polystyrene is all that’s left

Station 5: Cutting Apple Type of Change: Chemical Here’s Why: Apples discolour or turn brown when peeled or bruised and exposed to air. This discolouration or browning is due to oxygen, O2, reacting with chemicals released, breaking down the cells in the fruit. The reaction is called enzymatic oxidation as it is a process catalysed by the enzymes present in the apples.

Station 6: Baking Soda and Vinegar Chemical Type of Change: Here’s Why: CH3COOH + NaHCO3  CH3COONa + CO2 + H2O. This required energy, so it is endothermic—got cold to the touch.

Station 7: Baking soda (NaHCO3) + Perioxide Chemical Type of Change: Here’s Why: 2NaHCO3 + H2O2(l) --> Na2CO3 + 2H2O(l) + CO2(g)

Now for the Conclusion… What are the 4 parts? How long should it be? What all should I talk about?