Question

I need help with this chemistry equation

Answer 1

First write an equation with the elements
4Fe + 3O2 —> 2Fe2O3

So you’re given 25.4 g of iron which you must convert to moles

(25.4 g Fe/55.85g/mol)

This will give you moles of Fe but now you must use a mole ratio to get to grams of O2

(3 mol O2/4 mol Fe)

Now you’re in moles of O but you want grams so multiply by 32 g/mol (not 16 bc it’s O2)

(32 g/mol)
So the end equation should look like

(25.4 g Fe/55.85g/mol) (3 mol O2/4 mol Fe) (32 g/mol) = 10.9 g O2