Burning sulpher

Burning sulpher

ZIMSEC O Level Combined Science Notes: Experiment: Making acidic and alkaline solutions

Aim: To make acidic and alkaline solutions

Materials: sodium oxide, magnesium oxide, aluminium oxide, zinc oxide, unversal indicator, deflagrating spoon, sulpher, powdered carbon


  1. Dissolve a very small amount of sodium oxide in half a test tube of water
  2. Add 2 drops of universal indicator solution and note the pH of the solution
  3. Repeat the experiment using magnesium oxide, zince oxide and aluminium oxide taking note of the pH each time
  4. The oxide of sulpher is a gas. Set up the experiment as shown above by burning a small amount of sulpher in a deflagrating spoon and collecting the gas in a gas jar
  5. Add about 10cmof water into the gas jar, cover it and shake well
  6. Add Universal indicator to the solution and take note of its pH
  7. Repeat the steps using powdered carbon instead of sulpher

Results and Observations

OxidepH of solutionSoluble/Insoluble in water
Sodium oxideStrong alkaline/BaseReacts violently with water which is visible in the water solution
Magnesium oxideAlkaline/BasicNot soluble/very small amounts dissolve
Aluminium oxideAlkaline/BasicIs insoluble
Zinc oxideAlkalineIs insoluble
Sulpher dioxidestrong acidFairly soluble
Carbon dioxideweak acidvery small amounts dissolve


  • The oxides of metals form bases
  • Their solutions when they do dissolve in water are alkali
  • The oxides of non-metals form acids
  • Their solutions when they dissolve in water are acidic

NB The bases listed above react with the water which gives the impression of them dissolving

To access more topics go to the Combined Science Notes page.