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?

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.)

To determine the total mass of the set-up after the chemical is completely burned, we need to consider the chemical reaction that takes place.

When the chemical is ignited and burns, it undergoes a reaction with oxygen in the air and converts into different compounds. The reaction results in the formation of new substances, which may have different masses compared to the original chemical and oxygen.

Since the reaction takes place in a closed system (the sealed glass container), the mass of the system should remain constant according to the law of conservation of mass. This means that the total mass of the set-up should remain the same before and after the reaction.

In this case, the initial total mass of the set-up is 1000 grams (200 grams for the glass container + 800 grams for the chemical). According to the law of conservation of mass, the total mass of the set-up after the chemical is completely burned should also be 1000 grams.

Therefore, after the chemical is burned, the total mass of the set-up remains 1000 grams.