Question

One mole of any gas occupies 22.4 L under certain conditions of temperature and pressure. Assume those conditions for this question.

In a spacecraft, this reaction occurs:
CO2(g)+2LiOH(s)→CaCO3(s)+H2O(l)
How many liters of carbon dioxide will 2 moles of lithium hydroxide (LiOH) absorb?
Answer choices: A .3.0 L B .6.0 L C. 23 L D 45 L

Answer 1

The balanced chemical equation shows that one mole of CO2 is consumed in the reaction for every two moles of LiOH:
CO2(g) + 2LiOH(s) -> CaCO3(s) + H2O(l)
We can use this information along with the given molar volume of a gas at standard temperature and pressure to calculate the volume of carbon dioxide that will react with 2 moles of LiOH.
2 moles of LiOH will react with 1 mole of CO2, according to the stoichiometry of the balanced equation. Therefore, we need to find the volume occupied by 1 mole of CO2, which is 22.4 L at standard temperature and pressure.
So, the volume occupied by 1 mole of CO2 is 22.4 L.
Thus, the 2 moles of LiOH will require 1 mole of CO2 to react, which is equivalent to 22.4 L of CO2.
Therefore, 2 moles of LiOH will absorb 22.4 L of CO2.