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Edexcel IGCSE Biology · Spec 2.50

Investigating Carbon Dioxide in Exhaled Air

Covers compare carbon dioxide in inhaled and exhaled air, Use a suitable indicator and control and Design a safe and repeatable method.

Biology revision video

Investigating Carbon Dioxide in Exhaled Air

Spec 2.50

What you need to know

  • Compare carbon dioxide in inhaled and exhaled air
  • Use a suitable indicator and control
  • Design a safe and repeatable method

Active recall

Quick check

Answer each question before opening the answer.

Why does exhaled air contain more carbon dioxide?

Carbon dioxide is produced by respiration and transported to the lungs

Name two variables that must be controlled

Any two from indicator volume, air volume, flow rate, temperature and starting colour

What colour change is expected with more carbon dioxide?

Hydrogencarbonate indicator changes towards yellow

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