Question

Calculate the mass of iron(|||) oxide (rust) produced by the reaction of 500 g of iron with oxygen from the air

Answer 1

4Fe + 3O2 = 2Fe2O3

$Moles =mass/rmm$

If 500g of Fe react then, 500/55.8=9moles reacted.

The mole ratio of Fe:Fe2O3=4:2= 2:1

Therefore if 9 moles of Fe reacted 4.5 moles of Fe2O3 are produced

$Mass=moles \times rmm$

Mass of Fe2O3= 4.5* 159.7= 718.7g