In an experiment a student burns 27.6 kg of wood. He collects all the products, finding that it produced 1.3 kg of ash, 45.4 kg of carbon dioxide, and 24.3 kg of water. How many kilograms of oxygen were consumed in the burning process?

1 Answer
Dec 13, 2017

Well mass is conserved in every chemical reaction....

Explanation:

We know that wood will combust to give carbon dioxide and water and some salts...The products have a combined mass of #(1.3+45.4+24.3)*kg=71*kg#.

And thus the reactants ALSO had a combined mass of #71*kg#. We can account for #27.6*kg# of this mass.....the difference #(71-27.6)*kg=43.4*kg# MUST be due to oxygen....thus #43.4*kg# were consumed in the combustion.