How many liters of oxygen gas can react with 84.0 grams of lithium metal at standard temperature and pressure? Show all of the work used to find your answer.

4Li + O2 2Li2O
@nechirwan
This one isn't multiple choice but I really need help answering it!

Question

How many liters of oxygen gas can react with 84.0 grams of lithium metal at standard temperature and pressure? Show all of the work used to find your answer.

4Li + O2  2Li2O
@nechirwan 
This one isn't multiple choice but I really need help answering it!

nechirwan · Answer

4 Li + O2 -----> 2 LiO2 
moles Li: 84 g/ 6.94 g/mole Li= 12.1 moles Li 
from bal. rxn., 1 mole of O2 reacts with 4 moles O2 (1:4) 
1/4 x 12.1 moles Li= 3 moles of O2 
 1 mole =22.4 L 
3 x 22.4 L= 67.8 L of O2