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# Need help with a chemistry question please watch

1. Hello there, I would be grateful if anybody could help me with this question...

Sodium can form three oxides:

sodium oxide, Na2O

sodium peroxide, Na2O2

sodium superoxide, NaO2

It has been suggested that sodium superoxide could be used in spacecraft to
regenerate oxygen.

Oxygen needs to be replaced in a spacecraft because an astronaut oxidises glucose, according to the equation:
C6H12O6+ 6O2 → 6CO2+ 6H2O

Sodium superoxide can regenerate oxygen according to the equation:
4NaO2 + 2CO2 → 2Na2CO3+ 3O2

In order to maintain the correct percentage of oxygen in the air, any excess carbon dioxide could be removed by using sodium oxide.
Na2O + CO2 → Na2CO3

(a) Calculate the mass of sodium oxide that would be required to remove the excess
carbon dioxide when exactly 880 g of sodium superoxide is reacted per day.
You can assume that an astronaut oxidises 2 mol of glucose each day.

The MS gives an answer of 248g and I was wondering if anybody could help me figure out how they got that. Thanks again.
2. (Original post by Dank chemist)
Hello there, I would be grateful if anybody could help me with this question...

Sodium can form three oxides:

sodium oxide, Na2O

sodium peroxide, Na2O2

sodium superoxide, NaO2

It has been suggested that sodium superoxide could be used in spacecraft to
regenerate oxygen.

Oxygen needs to be replaced in a spacecraft because an astronaut oxidises glucose, according to the equation:
C6H12O6+ 6O2 → 6CO2+ 6H2O

Sodium superoxide can regenerate oxygen according to the equation:
4NaO2 + 2CO2 → 2Na2CO3+ 3O2

In order to maintain the correct percentage of oxygen in the air, any excess carbon dioxide could be removed by using sodium oxide.
Na2O + CO2 → Na2CO3

(a) Calculate the mass of sodium oxide that would be required to remove the excess
carbon dioxide when exactly 880 g of sodium superoxide is reacted per day.
You can assume that an astronaut oxidises 2 mol of glucose each day.

The MS gives an answer of 248g and I was wondering if anybody could help me figure out how they got that. Thanks again.

Where have you got to so far?
3. (Original post by h3rmit)
Where have you got to so far?
Well the only thing I know is that 2 moles of glucose produces 12 moles of carbon dioxide. I don't really know what to do with that information though lol.
4. (Original post by Dank chemist)
Well the only thing I know is that 2 moles of glucose produces 12 moles of carbon dioxide. I don't really know what to do with that information though lol.
Find how many moles of sodium superoxide 880g will produce, that tells you how much carbon dioxide you'll use from the spaceship when regenerating oxygen. The moles of glucose will tell you how much carbon dioxide you add when respiring. The difference iof carbon dioxide s what will have to be absorbed, so find how many moles of CO2 that would be and use that in the sodium oxide equation to find out how many grams of sodium oxide you need
5. Just tried it with this method and it worked. This is an interesting question though, can I ask where you got it from?
6. It's from an a-level chemistry sample paper on edexcel 's website. I was doing some practice questions and got stuck on this one unfortunately.

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7. Okay so I've finally got my head around it now. Thank you for taking time out of your day to help me. It is greatly appreciated.

-Dank chemist

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Updated: January 22, 2017
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