Higher chemistry unit 3

Question

5

Chemicals are used to remove the carbon dioxide breathed out by the crew

in spacecraft.

(a) In Apollo spacecraft, lithium hydroxide was used to remove carbon dioxide.

2LiOH(s) + CO₂(g) → Li₂CO3(aq) + H₂O(l)

mass of one mole = 23-9 g(of 2LiOH )

An Apollo spacecraft carried a three person crew.

Each crew member breathed out 12 litres of carbon dioxide every hour. Calculate the mass, in g, of lithium hydroxide required to absorb the carbon dioxide breathed out by the crew in 1 hour. (Take the molar volume of carbon dioxide to be 24 litres mol-¹.)

3

Answer 1

Start with the extensive variable (in this case 1 hour) and cancel units with the appropriate conversion factors or information given and/or known from chemistry knowledge.

1 hr (12 l CO₂/hr)(1 mole/22.4 l CO₂)(2 moles LiOH/mole CO₂)(23.95 g/mole LiOH) = g LIOH

That's for 1 person. Adjust for 3 people.