Chemical reaction: C + O₂ → CO₂.
Law of conservation of mass states that for any system closed to all transfers of matter and energy, the mass of the system must remain constant over time.
In chemical reactions, the mass of the chemical components before the reaction (in this reaction carbon and oxygen) is equal to the mass of the components after the reaction (carbon dioxide).
If we use one mole of substances, that:
mass of reactants is: 12 g (C) + 2·16 g (O) = 44 g.
mass of product is: 12 g + 32 g = 44 g.
