Answer:
The mass of the products and the mass of the reactants are equal.
Step-by-step explanation:
According to the Law of Conservation of Matter, matter cannot be created or destroyed in a chemical reaction. In the given chemical reaction of hydrogen and oxygen combining to form water, the reactants are hydrogen and oxygen, and the product is water. COM states that the total mass of the hydrogen and oxygen reactants must be equal to the total mass of the water product.
2H2+O2 -> 2H2O