The rusting of iron is due to its reaction with oxygen. An iron nail weighing 8.531 g was left outdoors for a period of one year. After the one year it was found to have a mass of 12.197 g. How many grams of oxygen did the nail react with

m (O₂) = 3.666 g

Explanation:

The rusting of iron is due to its reaction with oxygen. The balanced equation is:

4 Fe + 3 O₂ → 2 Fe₂O₃

According to Lavoisier's law of conservation of mass, the sum of the masses of the reactants is equal to the sum of the masses of the products.

m (reactants) = m (products)

m (Fe) + m (O₂) = m (Fe₂O₃)

8.531 g + m (O₂) = 12.197 g

m (O₂) = 3.666 g