Question

In the reaction `4Fe + 3O_2 -> 2Fe_2O_3`, how many grams of `Fe_2O_3` are produced from `73.2g` `Fe`?

Answer 1

104.6 g of `"Fe"_2"O"_3`.

Explanation:

This can be solved through dimensional analysis.

Atomic Masses:

`"Fe = 55.85 g/mol"`
`"O = 16.00 g/mol"`

Formula Mass:

`"Fe"_2"O"_3 ="159.69 g/mol"`

`"Moles of Fe" =73.2cancel("g Fe") xx ("1 mol Fe")/(55.85cancel("g Fe")) = "1.31 mol Fe"`

`"Moles of Fe"_2"O"_3 =1.31 cancel("mol Fe") xx ("2 mol Fe"_2"O"_3)/(4cancel("mol Fe")) = "0.655 mol Fe"_2"O"_3`

`"Mass of Fe"_2"O"_3 = 0.655cancel("mol Fe"_2"O"_3) xx ("159.69 g Fe"_2"O"_3)/(1 cancel("mol Fe"_2"O"_3)) = "104.6 g Fe"_2"O"_3`