Question

A chemical equation is balanced according to the law of:
A. multiple proportions
B. constant proportions
C. reciprocal proportions
D. conservation of mass

Answer 1

Chemical reaction which is represented in the form of symbols (substances) is known as a chemical equation. A chemical reaction or equation consists of reactants, products, and an arrow showing the direction of the reaction and the product. A chemical reaction which contains the same number of atoms of all the molecules on both sides is known as a balanced chemical equation.

Complete step by step answer:
Balancing of a chemical equation is governed by the law of conservation of mass. According to the law of conservation of mass, mass can neither be created nor destroyed in a chemical reaction due to this the total mass of the element present on the reactant should be equal to the total mass of the element present on the product side. If a chemical reaction does not follow the law of conservation of mass then the chemical reaction is said to be an unbalanced chemical equation.
After discussing we can conclude that a balancing of a chemical equation is according to the law of conservation of mass.

So, the correct answer is Option D.

Note: The stoichiometric coefficient shows the total number of molecules of a chemical species that participate in the chemical reaction.
The stoichiometric coefficient provides a ratio between the reacting species and the products formed in the chemical reaction.
Let us take an example of a reaction which is described by the equation
$C{H_4} + 2{O_2} \to C{O_2} + 2{H_2}O$
Here we can see that the stoichiometric coefficient of $C{H_4}$ and $C{O_2}$ is 1 and the stoichiometric coefficient of ${O_2}$ and ${H_2}O$ is 2.
For example, the total number of oxygen atoms present in the reactant side is $2{O_2}$ and is equal to 4.
When we balance a chemical equation the stoichiometric coefficient is assigned in such a way that balances the total number of atoms of an element on the reactant and the product side.