Question

Why should a chemical reaction always be balanced

Answer 1

The law of conservation of matter

Matter can change form through physical and chemical changes, but through any of these changes, the matter is conserved. The same amount of matter exists before and after the change—none is created or destroyed. This concept is called the Law of Conservation of Mass.

Chemical equation

A chemical equation is used to represent any type of chemical reaction in which a reactant is converted into a product under some specific conditions. A Chemical Reaction is a process that happens when two or more species interact to produce a new product

Explanation

• The Compounds that react in the reaction are called reactants whereas the compound that is newly formed is called the product
• In an equation, the reactants are written on the left-hand side and the products are written on the right-hand side demonstrated by one-headed or two-headed arrows.
• A chemical equation should always be balanced because the law of conservation of mass states that matter can neither be created nor destroyed
• $\therefore$ in a chemical equation the total mass of reactants must be equal to the mass of products formed which means the total number of atoms of each element should be equal on both sides of a chemical equation

Example $\underset{\mathrm{Nitrogen}}{{\mathrm{N}}_2}+\underset{\mathrm{Hydrogen}}{3{\mathrm{H}}_2}\rightleftharpoons \underset{\mathrm{ammonia}}{2{\mathrm{NH}}_3}$

Here,

ELEMENT	NO. OF ATOMS IN REACTANT SIDE	NO. OF ATOMS IN PRODUCT SIDE
$\mathrm{N}$	2	2
$\mathrm{H}$	6	6

Therefore, a chemical equation should always be balanced complying with the law of conservation on mass