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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: vicereine on July 14, 2008, 10:00:42 AM

Title: moles, grams, mole ratio unit changer
Post by: vicereine on July 14, 2008, 10:00:42 AM

The carbon dioxide that is exhaled by astronauts who are on a space shuttle is scrubbed by pumping the air through canisters of lithium hydroxide, LiOH. The chemical equation for this reaction is:

2 LiOH(s) + CO2(g) -> Li2CO3(s) + H2O(l)

a) What mass of carbon dioxide can 1.00 kg of lithium hydroxide absorb?

b) What mass of lithium carbonate, Li2CO3, is produced?

I checked online to see if I did it right and actually found 2 posts with the same question, however both say something different than I got:

http://au.answers.yahoo.com/question/index?qid=20080404104720AAAEYM0 (http://au.answers.yahoo.com/question/index?qid=20080404104720AAAEYM0)
http://answers.yahoo.com/question/index?qid=20071115173257AApduDa (http://answers.yahoo.com/question/index?qid=20071115173257AApduDa)

My answers are in the attachment, if someone could let me know if I got it right or not!

Title: Re: moles, grams, mole ratio unit changer
Post by: DrCMS on July 14, 2008, 10:24:46 AM

a) looks OK
b) check the molecular mass of lithium carbonate

Title: Re: moles, grams, mole ratio unit changer
Post by: Borek on July 14, 2008, 10:34:03 AM

Upper frame - initial data. Lower frame - results.

Title: Re: moles, grams, mole ratio unit changer
Post by: vicereine on July 14, 2008, 10:41:18 AM

Quote from: DrCMS on July 14, 2008, 10:24:46 AM

a) looks OK
b) check the molecular mass of lithium carbonate

oops I didn't edit that part, I had forgotten the 2 for Li2 in the initial calculations, the answer is supposed to be 1543.93 g

ps how many decimal points should I use, just one?

Title: Re: moles, grams, mole ratio unit changer
Post by: Borek on July 14, 2008, 11:02:01 AM

How many significant digits in 1.00?