Question

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 750 grams. the total mass of the setup is 950 grams. the chemical is ignited by means of a magnifying glass focusing sunlight onto the reactant. after the chemical has completely burned, what is the total mass of the setup?

Answer 1

After the chemical has completely burned, the total mass of the set up remains being the same than before: 950g.

The mass is conserved during chemical reactions; this is, the mass of the reactants is equal to the mass of the products, so there is not change in mass, and you can conclude quickly that the mass of the set up at the end is 950, the same of starting.