05. Oxygen and oxides

image: https://www.neechamber.co.uk/policy/connecting-for-innovation/case-studies

Objectives:

- Observe how different elements react with oxygen (oxidise) to make new products.

- Test and observe the properties of the oxides.

- Hypothesise explanations for the properties based on the location of elements in the Periodic Table.

Demonstration:

Watch and make notes as Carbon (charcoal), Sulfur and Sodium are reacted with oxygen to make their corresponding oxides.

Activity:

Carefully burn samples of magnesium and copper in air to make their oxides.

Method:

• 1. Clean the deflagrating spoon in water and then heat in the Burner flame to make sure it is clean.

  2. Place a small sample of the material to be tested (either copper or magnesium) in the deflagrating spoon and then heat using the Burner flame until the sample has completely reacted with oxygen.

  3. Record your (qualitative observations) in your notes.

  4. Place the sample in small beaker and keep for later.

  5. Repeat the process for the other sample.

Demonstration:

Watch and make notes as the oxides made earlier are dissolved in water and then tested with universal indicator to check the pH of the solution.

Activity:

Dissolve the two products you made earlier in water and test the pH of the resultant solution using universal indicator. What observations do you make.

Activity:

Locate the 5 samples that were tested on a periodic table. Is there any relationship between their position on the Periodic Table and the pH of the solution they make.

Speculate as to what might be the reason for the difference.

Next Lesson: Causes of rusting