If 19.2 grams of O2 reacts with iron to form iron oxide how much iron was used in the reaction? use the equation 4Fe + 3O2 — 2Fe2O3 to help

44.8g

Explanation:

The reaction equation is given as:

        4Fe + 3O₂  →  2Fe₂O₃

Given:

Mass of O₂   = 19.2g

Unknown:

Amount of iron used  =?

Solution:

To solve this problem, we adopt the mole concept.

   Since we know the mass of O₂;

         Number of moles  =  

 Molar mass of  O₂ = 2(16)  = 32g/mol

           Number of moles =   = 0.6moles

From the balanced reaction equation;

           4 moles of Fe will react with 3 moles of O₂

          0.6moles of O₂ will react with   = 0.8mole of Fe

Mass of Fe  = number of moles x molar mass

                    = 0.8 x 56

                     = 44.8g

yes the answer is total mass in unchanged   : )