As you know, all animals exhale carbon dioxide in the process of breathing. In a closed environment such as the space shuttle, a build-up of carbon dioxide can be deadly. CO₂ in high enough concentrations in a closed environment can replace oxygen making it difficult to breathe enough oxygen to survive. Astronauts in the space shuttle rely on methods that continuously take carbon dioxide out of the air. A device in the space shuttle uses lithium hydroxide to remove carbon dioxide. Carbon dioxide will react with aqueous hydroxide ion to produce hydrogen carbonate ion.

In this lab you build a similar device to remove CO₂ from the atmosphere of a petri dish that uses sodium hydroxide.