Question

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

Answer 1

44.8g

Step-by-step 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 =
`(mass)/(molar mass)`

Molar mass of O₂ = 2(16) = 32g/mol

Number of moles =
`(19.2)/(32)` = 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
`(0.6 x 4)/(3)` = 0.8mole of Fe

Mass of Fe = number of moles x molar mass

= 0.8 x 56

= 44.8g