CO2
a poison that must be
removed
Design an air
filtering system for a submarine? This filter must remove odours and
carbon dioxide from the air. Conduct some experiments to see how best to
remove odours. Try using common
household baking powder and discuss your
results. Indicate where the air
is channelled and what reactions take place. For long space voyages discuss how best to
provide oxygen and remove carbon
dioxide? Carbon dioxide is
toxic to the astronauts. If its concentration is allowed to increase it
will be fatal. The Orbiter has special air filters containing lithium
hydroxide. The air is passed through the filters and any carbon dioxide
present reacts with the
lithium hydroxide to produce a harmless solid substance called
lithium carbonate. Just like the movie above calcium hydroxide (lime
water) works in a similar way to lithium hydroxide. As carbon dioxide is
bubbled through lime water solid calcium carbonate is formed. Calcium
carbonate is non toxic, in fact it is the substance the normal chalk is
made up of. The filtered air has
no carbon dioxide, all the carbon dioxide has reacted to form lithium
carbonate. Lithium carbonate stays in the filters as a solid
substance. When
CO2 is bubbled through water containing calcium hydroxide (lime
water) a solid white substance is formed. This white solid has the
chemical name calcium
carbonate.