When carbon is burned in air, it reacts with oxygen to form carbon dioxide. when 22.8g of carbon were burned in the presence of 78.0 of oxygen, 17.2g of oxygen remained unreacted. what mass of carbon dioxide was produced?

83.6 g  

Explanation:

The limiting reactant is carbon and oxygen is in excess.

C + O₂ ⟶ CO₂

Data:

                  Mass of C = 22.8 g

                 Mass of O₂ = 78.0 g

Mass of unreacted O₂ =  17.2 g

Calculations:

          Mass of O₂ reacted = 78.0 g  -  17.2 g = 60.8 g

Mass of reactants (C + O₂) = 22.8 g + 60.8 g = 83.6 g

According to the Law of Conservation of Mass, the mass of the product (CO₂) equals the sum of the masses of the reactants.

The mass of CO₂ is 83.6 g.