Here's a chemical equation that demonstrates the law of conservation of mass:

2H₂ + O₂ → 2H₂O

Explanation:

* Reactants:

* 2H₂ (two molecules of hydrogen gas)

* O₂ (one molecule of oxygen gas)

* Products:

* 2H₂O (two molecules of water)

Analysis:

* Hydrogen (H): There are 4 hydrogen atoms on the reactant side (2 x 2 = 4) and 4 hydrogen atoms on the product side (2 x 2 = 4).

* Oxygen (O): There are 2 oxygen atoms on the reactant side and 2 oxygen atoms on the product side.

Conclusion:

The equation is balanced because the number of each type of atom is the same on both sides of the equation. This demonstrates the law of conservation of mass, which states that in a closed system, mass cannot be created or destroyed during a chemical reaction. The total mass of the reactants (hydrogen and oxygen) equals the total mass of the product (water).