If each astronaut exhales 18.2 mol of CO2 every day and the mission is eight days, what mass of LiOH would exactly meet the requirement?

Question

When the engineers were designing Apollo 13, they had to estimate the amount of CO2 that each astronaut would exhale. Unlike the Lunar Module, the Command and Space Module had enough LiOH to scrub all of the CO2 exhaled by the three men. If each astronaut exhales18.2 mol of CO2 every day and the mission is eight days, what mass of LiOH would exactly meet the requirement?

Answer 1

I'll assume the lithium hyrroxide is used to remove the CO2 as per:

2LiOH + CO₂ → Li₂CO₃ + H₂O

A key benefit is the production of water.

Astronauts exhale at a rate of 18 moles CO2/astronaunt. The above balanced equation tells us the 2 moles of LiOH are required for each 1 mole of CO2. The design would need to have 36 moles/day of LiOH for each astronaunt.

(36 moles/day/astronaunt)*(3 astronaunts)(8 days) = 2590 moles

(2590 moles)*(23.94 g/mole) = 6.20x10^4 grams, or 62 kg.