Physical Science December Lab Exam

Labs You are Responsible For:

1. Conversion of Cu into a Compound

· Colour changes occurred, suggesting it was a chemical change

· Mass of copper increases because it bonded to oxygen

2. Converting CuO back into an Element

· C was used to remove oxygen from CuO

· The black CuO turned golden brown, suggesting a chemical change(golden brown was colour of Cu)

· Mass of Cu was less than that of CuO, and gas escaped(CO₂), proving that CuO was a compound and not an element

3. Solids and Liquids: Electrolytes, Nonelectrolytes

· Electrolytes are aqueous solutions that conduct electricity. Acids, bases and salts, when dissolved in water, all form electrolytes and cause an conductivity apparatus to turn on.

· Acids can be distinguished from bases based on their reaction with litmus paper

4. Characteristic tests for Various Elements and Compounds

Substance	Characteristic test
H2O	Turns blue cobalt chloride paper pink.
O2	Causes a glowing splint to burst into flames.
H2	A popping sound results when flame is placed in a test tube of hydrogen.
CO2	Only gas capable of turning limewater milky.

5. Metals, Nonmetals and Metalloids(Was done as a demo but you will have to perform)

What tests can be used to distinguish between them? See yellow booklet: section on metalloids.