F2 IS EXP 02 Answers

1st Term EXP 02 Submission date：_____________ Name：______________________ Class & no.：2 _________(     )

Experiment 7.1A: C: Comparing比較 the oxygen and

carbon dioxide content of breathed air未經呼吸的空氣

and unbreathed air呼出的空氣

Results結果:

B. Comparing the oxygen content

	Breathed air	Unbreathed air
Time taken for burning splint to go out (s)	(less time)	(more time)

C. Comparing the carbon dioxide content

	Breathed air	Unbreathed air
Colour of hydrogencarbonate indicator after shaking	yellow	red

Conclusion結論:

Ø   Breathed air contains less oxygen than unbreathed air.

Ø   Breathed air contains more carbon dioxide than unbreathed air

Experiment 7.1E: Compare the water vapour content of breathed air and unbreathed air

Results:

	Under breathing	Without breathing沒有呼吸
Colour change of the cobalt chloride paper	Changes from blue to pink	Remains unchanged / the colour changes very slowly

Conclusion:

Ø   Breathed air contains more water vapour than unbreathed air.