the grams of oxygen gas that can be produced is 20.6 grams of o₂
calculation
2liclo₃ → 2 licl + 3 o₂
step 1: find the moles of liclo₃
moles = mass÷ molar mass
from periodic table the molar mass of liclo₃ =6.9 +35.5 +(16 x3) =90.4 g/mol
moles=38.7 g÷90.4 g/mol=0.4281 moles
step 2: use the mole ratio to calculate the moles of o2
from equation above, liclo₃: o₂ is 2: 3
therefore the moles of o₂=0.4281 moles x3/2 =0.6422 moles
step 3: find mass of o₂
mass= moles x molar mass
from periodic table the molar mass of o₂ = 16 x2= 32 g/mol
mass=0.6422 moles x 32 g/mol = 20.6 grams of o₂