In a spacecraft, the carbon dioxide exhaled by astronauts can be removed by its reaction with lithium hydroxide (LiOH) according to the following chemical equation:

[tex]\[ CO_2 (g) + 2 \, \text{LiOH} (s) \rightarrow \text{Li}_2 \text{CO}_3 (s) + \text{H}_2 \text{O} (l) \][/tex]

How many moles of lithium hydroxide are required to react with 20 mol of [tex]\( CO_2 \)[/tex], the average amount exhaled by a person each day?

A. 40 moles
B. 20 moles
C. 80 moles
D. 10 moles



Answer :

To determine how many moles of lithium hydroxide (LiOH) are required to react with 20 moles of carbon dioxide (CO₂), we can use the stoichiometric relationship given in the balanced chemical equation:

[tex]\[ CO_2(g) + 2 LiOH(s) \rightarrow Li_2CO_3(s) + H_2O(l) \][/tex]

From the balanced equation, we see that 1 mole of CO₂ reacts with 2 moles of LiOH. This gives us the stoichiometric ratio:

[tex]\[ 1 \text{ mole of } CO_2 : 2 \text{ moles of } LiOH \][/tex]

Now, let's determine how many moles of LiOH are needed to react with 20 moles of CO₂.

Step-by-step procedure:

1. Identify the given quantity: We know that we have 20 moles of CO₂.
2. Use the stoichiometric ratio to find the required amount of LiOH:
[tex]\[ \text{Moles of LiOH} = 2 \times \text{Moles of CO₂} \][/tex]
3. Substitute the given quantity (20 moles of CO₂) into the equation:
[tex]\[ \text{Moles of LiOH} = 2 \times 20 \text{ moles of CO₂} \][/tex]
4. Calculate the result:
[tex]\[ \text{Moles of LiOH} = 40 \text{ moles of LiOH} \][/tex]

Therefore, 40 moles of lithium hydroxide (LiOH) are required to react with 20 moles of carbon dioxide (CO₂), which is the average amount exhaled by a person each day.

Based on our calculation, the correct answer is:

- 40 moles