Test for carbon dioxide. Apparatus for comparing the carbon dioxide (CO2) content of inhaled and exhaled air. The two test tubes contain saturated cal

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Test for carbon dioxide. Apparatus for comparing the carbon dioxide (CO2) content of inhaled and exhaled air. The two test tubes contain saturated calcium hydroxide solution (Ca(OH)2, lime water) which reacts with CO2 to produce a cloudy precipitate (calcium carbonate CaCO3). Breathing in through the red tube (top) draws air through the lime water in the left test tube. This air has a low CO2 content so no reaction occurs. Breathing out through the same tube pushes exhaled air through the lime water in the right test tube. Exhaled air has a high CO2 content, so the limewater turns cloudy.

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Size: 3650px × 4874px
Photo credit: © MARTYN F. CHILLMAID/SCIENCE PHOTO LIBRARY / Alamy / Afripics
License: Licensed
Model Released: No

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