When iron reacts with oxygen, it forms iron oxide, or rust. 4 Fe + 3 O2 2 Fe2O3 If 112 g of iron (Fe) combines with 24 g of oxygen (O2), how much iron oxide is formed? (88 g Fe2O3) (112 g Fe2O3) (24 g Fe2O3) (136 g Fe2O3)

I'm not going to give you the answer but I will tell you how to get the answer...  First find out the moles of oxygen by doing mass over molar mass (24/32)  Then find use the mole ratio (unknown/known) 2/3 then times by the moles of oxygen Then you have the moles of Fe2O3 Then to get the mass you will need to times it by the molar mass to get the mass   Hope this helps and isn't too much of a pain to figure out but what I have learnt is that it's better to get taught how to work it out rather than just getting the answer. Trust me this will help in the future when it comes to calculations in Chem :)

the answer is ( 136 g Fe203) i hope that helps you