Discrepancy is the difference between these
two masses
Initial mass 
cartridge________gbag _________ g
cartridge________gbag _________ gFinal mass ________g __________g
________g __________gChange in mass ________g __________g
________g __________gDiscrepancy: _________g
Moles of Butane in bag: n = _____ moles
Change in cartridge
mass
58.124 g/mole
calculate