Chemistry  please help!
posted by Alex .
The decomposition of KClO3 produces oxygen gas and solid KCl. What mass of KClO3 must be decomposed to produce 126 L of oxygen gas at 133 Celsius and .88 atm?
I know I need to use PV=nRT but I can't figure out how.

Here is a worked example on the decomposition of KClO3. To convert 126 L O2 to n = mols, use PV = nRT and solve for n, then follow the instructions beginning with step 3.
http://www.jiskha.com/science/chemistry/stoichiometry.html 
thank you!