The chemical equations are balanced to satisfy one of the following laws in chemical reactions. This law known as :

(a) law of conservation of momentum

(b) law of conservation of mass

(c) law of conservation of motion

(d) law of conservation of magnetism

Law of conservation of mass.

When we balance an equation, we determine the ratio of reactants to products which allows for the total number of atoms of reactants to match the number of atoms of the products. Since the type of atoms does not change and the number of atoms stays that same, the total mass that goes into the chemical change will match the mass that comes out after the change.