Question

why do we need to balance an equation??​

Answer 1

To make sure about the law of conservation of mass.

This law states that the mass of reactants is always equal to the mass of products.

That's why we need to balance an equation.

Hope it helps

All the very best

Answer 2

we need to balance a chemical equation in order to satisfy the law of conservation of mass which states that in a chemical reaction the total mass of the reactants is equal to the total mass of the products.