Air and Combustion

Syllabus tag: KCSE | Chemistry | Form 1 | Topic 4 Air and Combustion

Lesson objectives

By the end of this topic, you should be able to:

• State the composition of air and determine the percentage of oxygen experimentally.
• Prepare oxygen and state its properties and uses.
• Describe burning in air and oxygen and write equations.
• Explain rusting and its prevention, and describe air pollution.

Summary

Air is a mixture of about 78 per cent nitrogen, 21 per cent oxygen and small amounts of noble gases, carbon dioxide and water vapour. Oxygen supports combustion and relights a glowing splint. Rusting requires both oxygen and water, and is prevented by excluding either.