Mass is conserved in all chemical reactions. This means that matter is neither created nor destroyed in a chemical reaction. For mass to be conserved, there must be equal numbers of each type of atom on both sides of the equation. See example below: Which chemical equation below correctly demonstrates the law of conservation of mass? a Na + CuS --> Na2S + Cu b H2O2 --> H2O + O2 c Zn + HCl --> ZnCl2 + H2 d K + AgCl --> KCl + Ag
