Final answer:
Understanding stoichiometry is essential for the precise calculation of chemical reactions in space missions, such as fuel for propulsion. High CO2 concentrations are harmful to astronauts, and systems like CDRA or backup LiOH canisters are used to control its levels. For six astronauts exhaling 0.55 moles of CO2 per hour, 158.07 grams of LiOH are required to absorb the CO2 hourly.
Step-by-step explanation:
Understanding stoichiometry is critical to a successful space mission because it allows for precise calculations of reactants and products in chemical reactions. For example, in the space shuttle, the propulsion system uses chemical reactions, such as combining liquid hydrogen with liquid oxygen to produce water. Accurate stoichiometric calculations ensure that the right amount of fuel is used, which is essential for the lift and maneuverability of spacecraft.
The presence of high concentrations of carbon dioxide (CO2) in a spacecraft can lead to negative health effects, including headaches, dizziness, shortness of breath, and even loss of consciousness. To prevent this, engineers have developed systems like the Carbon Dioxide Removal Assembly (CDRA), which eliminate excess CO2. In emergencies where the CDRA fails, lithium hydroxide (LiOH) canisters serve as a backup for absorbing CO2. The reaction is as follows: 2 LiOH(s) + CO2(g) → Li2CO3(s) + H2O(l).
To calculate the mass of lithium hydroxide needed to absorb the CO2 exhaled by six astronauts, we use stoichiometry. Each astronaut exhales 0.55 moles of CO2 per hour, so for six astronauts, that's 3.3 moles of CO2 per hour. With the given reaction, 2 moles of LiOH are required for every mole of CO2, therefore, 6.6 moles of LiOH are needed hourly. The molar mass of LiOH is approximately 23.95 g/mol, so the mass required per hour is 6.6 moles × 23.95 g/mol = 158.07 grams.