4mno2 = 2 mn2o3 + o2
46.8/86.93 .5383/2 (moles=molar mass/ weight)
=.5383 ( molar mass of mno2=86.93)
( molar mass of mn2o3=157.87)
moles 0f mn203= 1/2 moles of mn02 (from reaction)
moles 0f mn203= .5383/2=.269
grams of mn2o3=moles*molar mass
=.269*157.87
=42.49 grams