You have a chemical sealed in a glass container filled with air. The glass container has a mass of 200.0 grams and the chemical has a mass of 800 grams. The total mass of the set-up is 1000 grams. The chemical is ignited by means of a magnifying glass focusing sunlight onto the reactant. After the chemical is completely burned, what is the total mass of the set-up?

Answer 1

As long as the container is sealed, conservation of mass is conserved (i.e., 1,000 g is before the reaction and 1,000g after the reaction.)