ZIMSEC O Level Combined Science Notes: Inhaled vs Exhaled air experiment: Method 1
Aim: Test to compare the composition of exhaled and inhaled air.
Materials: Limewater (to test for the presence of carbon dioxide), corks, test tubes, glassware tubing shown below
- Set up the apparatus as shown above with an equal amount of lime water in each test tube.
- Breath in and out using the mouthpiece.
- Do this for a couple of minutes.
Results and explanation
- Air enters through the left and out to the right.
- The limewater in the right test tube turns milky.
- This shows that exhaled air has more carbon dioxide when compared with inhaled air.
- Limewater turns cloudy/milky when air containing carbon dioxide is blown into the test tube.
- Exhaled air contains more carbon dioxide compared to inhaled air.
To access more topics go to the Combined Science Notes page.