Answer:
Explanation:
so u can work out the amount of moles in FeO3 by doing mr of fe3o3 is 55.8*3+16*3=215.4
moles= mass/mr so you do 15.5g/215.4=0.0719 moles
then using 1 to 1 ratio so O2 moles is 0.0719
then use the equation mass=mole*mr
so 0.0719*16=1.15g
hope this make sense :)
