The chemical equation is balanced to satisfy one of the following laws in chemical reactions. This law is 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

Hint: Basically, the chemical equations are the symbolic representations of chemical reactions in which the reactants and products are expressed in terms of their respective chemical formulae. These equations satisfy the law that matter can be changed from one form into another but the total amount of mass remains constant.

Complete step by step answer:
The chemical equations are symbolic representations of chemical reactions. These reactions can be represented with the help of chemical equations for example we have to write the equation for the reaction between hydrogen gas and oxygen gas to form water. The equation is as shown:
 $2{H_2} + {O_2} \to {H_2}O$
Now, we can see that the reacting entities are written on the left whereas the products are written on the right-hand side. Moreover, there are many symbols which are used to represent a chemical equation. These chemical equations are further balanced and satisfy the law of conservation of mass. This law states that matter can be changed from one form to another but the total amount of mass remains constant. According to this law, the mass of products in a reaction must be equal to the mass of reactants so that the balancing is done and this law is obeyed.
Hence, option B is correct.

Note:Some of the examples of law of conservation of mass are the combustion process and various chemical reactions. In the combustion process, the burning of wood is a conservation of mass as it involves oxygen, carbon dioxide, water vapor and ashes.