Lesson Plan: C2.3.02

Hamble Lesson Observation Plan
Learning About
How can we use chemical tests to identify an unknown gas?
Keywords:
  • Litmus paper: paper stained with litmus which is used to indicate the acidity or alkalinity of a substance. (1)
  • Quantitative test (1)
  • Qualitative test: This type of test identifies whether a substance is present, but not how much of it exists. A common example would be using a pH indicator to see if an acid is present. (1)
  • Lime water: An aqueous solution of calcium hydroxide. (1)
Memory Anchor:
Method Precise Learning Objective Linked Question / Activity
(Designed for maximum working out)		 Stepping Stones Pitstop Check
(Thinking Map)
The test for carbon dioxide uses an aqueous solution of calcium hydroxide (lime water). When carbon dioxide is shaken with or bubbled through limewater the limewater turns milky (cloudy). How would you test if carbon dioxide was present In a reaction?

Practical: Testing for different gases - Hydrogen - Carbon dioxide - Oxygen - Chlorine Students to plan and investigate the gas tests
Students do not need to know the names of components in proprietary products.

The test for hydrogen uses a burning splint held at the open end of a test tube of the gas. Hydrogen burns rapidly with a pop sound How would you test if Hydrogen was present In a reaction?
The test for chlorine uses litmus paper. When damp litmus paper is put into chlorine gas the litmus paper is bleached and turns white. How would you test if chlorine was present In a reaction?
The test for oxygen uses a glowing splint inserted into a test tube of the gas. The splint relights in oxygen How would you test if Oxygen was present In a reaction?
Links To the Big Ideas
ForcesParticlesEnergyCells