Experiment WS 1: 7.1A &B

Kowloon Tong School (Secondary Section)

F.2 Integrated Science

Experiment Worksheets

Name: _________________ (    )                                                               Date: __________________

Class: 2 _______

Experiment 7.1A: Tests for oxygen and carbon dioxide

Objective:       To identify oxygen and carbon dioxide

Results:

Observation	Test results
	Oxygen	Carbon dioxide
1: colour of gas	colourless	colourless
2: smell of gas	odourless	odourless
3: change of burning splint	Burns more brightly	Goes out
4: change of glowing splint	Relights	Goes out
5: colour change of hydrogencarbonate indicator	No observable	Changes from red to
	changes	yellow
6: colour change of lime water	No observable	Changes from colourless
	changes	to milky

Discussion:

Ø   Oxygen can relight a glowing splints.

Ø   Carbon dioxide can turn lime water from colourless to milky.

Ø   Carbon dioxide can turn hydrogencarbonate indicator from red to yellow.

Experiment 7.1B: Tests for water and water vapour

Objective:       To carry out a simple test for water and water vapour.

Results:

Observation	Colour / Colour Change
	Dry	Wet
Cobalt chloride paper	blue	pink
Cobalt chloride paper in air	The colour changes from blue to pink

Discussion:

Ø   Cobalt chloride paper can be used to test for water.

Ø   From the result of dry cobalt chloride held in air for one to two minutes, we can conclude that air

contains water vapour.