When paper is burned,the mass of the remaining ash is less than the mass of the original paper.Which of the following is the best explanation for this apparent violation of the Law of Conservation of Mass?
A)Some of the mass is converted into the heat energy evolved from burning
B)When invisible substances are taken into account, the total mass of the reactants is equal to the total mass of the products
C)The ash is more dense than the paper
D)The different molecular structure of the ash causes it to appear to have less mass until it is compacted
E)The mass of the ash cannot be accurately determined

Question

Quizplus · Accepted Answer

The Law of Conservation of Mass states that mass is neither created nor destroyed in a chemical reaction. When paper burns, gases like carbon dioxide and water vapor are released into the air, which are not accounted for when only the mass of the ash is considered. If these gases were captured and their mass added to that of the ash, the total mass would equal the mass of the original paper, thus adhering to the Law of Conservation of Mass.

When Paper Is Burned,the Mass of the Remaining Ash Is