Iron(iii) oxide is formed when iron combines with oxygen in the air. how many grams of iron(iii) oxide are formed when 16.7 g of fe reacts completely with oxygen

Mass = 23.95 g

Explanation:

Mass of iron = 16.7 g

Mass of iron(iii) oxide formed = ?

Solution:

Chemical equation:

Fe + 3O₂ → 2Fe₂O₃

Number of moles of iron:

Number of moles = mas/ molar mass

Number of moles = 16.7 g/ 55.85 g/mol

Number of moles = 0.3 mol

Now we will compare the moles of iron and iron oxide.

                                Fe       :      Fe₂O₃

                                 4         :         2

                                0.3       :        2/4×0.3 = 0.15 mol

Mass of iron(iii) oxide:

Mass = number of moles × molar mass

Mass = 0.15 mol × 159.69 g/mol

Mass = 23.95 g