The carbon dioxide exhaled by astronauts can be removed from a spacecraft by reacting it with lithium hydroxide (LiOH). The reaction is as follows: CO2 (g) + 2LiOH (s) Li2CO3 (s) + H2O (l). An average person exhales about 20 moles of CO2 per day. How many moles of LiOH would be required to maintain two astronauts in a spacecraft for three days?

Question

The carbon dioxide exhaled by astronauts can be removed from a spacecraft by reacting it with lithium hydroxide (LiOH).  The reaction is as follows: CO2 (g) + 2LiOH (s) Li2CO3 (s) + H2O (l).  An average person exhales about 20 moles of CO2 per day.  How many moles of LiOH would be required to maintain two astronauts in a spacecraft for three days?

anonymous · Answer

Two astronauts would exhale about 40 moles of carbon dioxide daily.

Carbon dioxide reacts with lithium hydroxide in a 1 : 2 mole ratio. Set up a proportion:

1 : 2 = 40 : x

Then, find x:
$$\frac{1}{2} = \frac{40}{x}$$

Cross multiply.   x = 80 moles of LiOH per day for both astronauts