Question

How to balance the chemical equation.

Answer 1

Chemical equation :-

• A chemical equation is the chemical formula that contains information on the elements and molecules that are reacting as well as the molecules that are being created as a result of that reaction.
• According to the Law of Conservation of Mass, the mass of the reactants and the mass of the products must be equal.
• The atoms of all the elements and molecules on the reactant side (left side) and product side (right side) must be equal in order for a chemical equation to be balanced.

Steps to balance the chemical equation :-

Obtaining the entire imbalanced equation is the first step that must be taken when balancing chemical equations. The combustion interaction between Propane and Oxygen is used as an example to demonstrate this technique.

Step 1: Writing the imbalanced chemical equation:-

• It is necessary to determine the imbalanced equation from the chemical formulas of the reactants and products (if it is not already provided).
• Propane has a chemical formula${\mathrm{C}}_3{\mathrm{H}}_8$. When it burns with oxygen$\left({\mathrm{O}}_2\right)$, carbon dioxide $\left({\mathrm{CO}}_2\right)$ and water are produced $\left({\mathrm{H}}_2\mathrm{O}\right)$
• The imbalanced chemical equation is expressed as

Chemical Equation: $\underset{\mathrm{Propane}}{{\mathrm{C}}_3{\mathrm{H}}_8\left(\mathrm{l}\right)}+\underset{\mathrm{Oxygen}}{{\mathrm{O}}_2\left(\mathrm{g}\right)}\to \underset{\mathrm{Carbon}\mathrm{dioxide}}{{\mathrm{CO}}_2\left(\mathrm{g}\right)}+\underset{\mathrm{Water}}{{\mathrm{H}}_2\mathrm{O}}\left(\mathrm{l}\right)$

Step 2: Comparing the number of atoms on both reactant and product side :-

It is necessary to compare the total number of atoms of each element on the reactant side and the product side. The number of atoms on each side, in this case, can be tabulated as follows.

Reactant Side	Product Side
$3$ Carbon atoms from ${\mathrm{C}}_3{\mathrm{H}}_8$	$1$ Carbon atom from ${\mathrm{CO}}_2$
$8$ Hydrogen atoms from ${\mathrm{C}}_3{\mathrm{H}}_8$	$2$ Hydrogen atoms from ${\mathrm{H}}_2\mathrm{O}$
$2$ Oxygen atoms from ${\mathrm{O}}_2$	$3$ Oxygen atoms, $2$ from ${\mathrm{CO}}_2$ and $1$ from ${\mathrm{H}}_2\mathrm{O}$

Step 3: Balancing the Carbon atoms:-

• Since the reactant side and product side of an element have a differing number of atoms, stoichiometric coefficients are now added to those molecules.
• Each side's atom count must be balanced by the coefficient.
• Typically, the hydrogen and oxygen atoms get their stoichiometric coefficients last.
• It is now necessary to update the number of atoms in each element on the reactant and product sides.
• Remember that the stoichiometric coefficient must be multiplied by the total number of atoms of an element present in 1 molecule of the species to determine the number of atoms in one species.
• For instance, the ${\mathrm{CO}}_2$ molecule's total number of oxygen atoms increases to $6$ when the coefficient of $3$ is applied to it. In this illustration, the coefficient is initially given to carbon, as shown in the table below.

Chemical Equation: $\underset{\mathrm{Propane}}{{\mathrm{C}}_3{\mathrm{H}}_8}+\underset{\mathrm{Oxygen}}{{\mathrm{O}}_2}\to \underset{\mathrm{Carbon}\mathrm{dioxide}}{3{\mathrm{CO}}_2}+\underset{\mathrm{Water}}{{\mathrm{H}}_2\mathrm{O}}$

Reactant Side	Product Side
$3$ Carbon atoms from ${\mathrm{C}}_3{\mathrm{H}}_8$	$3$ Carbon atom from ${\mathrm{CO}}_2$
$8$ Hydrogen atoms from ${\mathrm{C}}_3{\mathrm{H}}_8$	$2$ Hydrogen atoms from ${\mathrm{H}}_2\mathrm{O}$
$2$ Oxygen atoms from ${\mathrm{O}}_2$	$7$ Oxygen atoms, $6$ from ${\mathrm{CO}}_2$ and $1$ from ${\mathrm{H}}_2\mathrm{O}$

Step 4: Balancing the Hydrogen and Oxygen atoms:-

• The third step is continued until both the reactant and product sides have the same amount of atoms of each reactive element.
• Hydrogen is then balanced in this illustration. The resulting chemical equation is as follows.

Chemical Equation: $\underset{\mathrm{Propane}}{{\mathrm{C}}_3{\mathrm{H}}_8}+\underset{\mathrm{Oxygen}}{{\mathrm{O}}_2}\to \underset{\mathrm{Carbon}\mathrm{dioxide}}{3{\mathrm{CO}}_2}+\underset{\mathrm{Water}}{4{\mathrm{H}}_2\mathrm{O}}$

Reactant Side	Product Side
$3$ Carbon atoms from ${\mathrm{C}}_3{\mathrm{H}}_8$	$3$ Carbon atom from ${\mathrm{CO}}_2$
$8$ Hydrogen atoms from ${\mathrm{C}}_3{\mathrm{H}}_8$	$8$ Hydrogen atoms from ${\mathrm{H}}_2\mathrm{O}$
$2$ Oxygen atoms from ${\mathrm{O}}_2$	$10$ Oxygen atoms, $6$ from ${\mathrm{CO}}_2$ and $4$ from ${\mathrm{H}}_2\mathrm{O}$

• After the hydrogen atoms have been balanced, oxygen must now be balanced. $10$ oxygen atoms are present on the product side, which suggests that $10$ oxygen atoms are likewise present on the reactant side.
• A single ${\mathrm{O}}_2$ molecule has two oxygen atoms in it. As a result, the ${\mathrm{O}}_2$ molecule must be given the stoichiometric coefficient of $5$. The revised chemical equation is shown in the table below.

Chemical Equation: $\underset{\mathrm{Propane}}{{\mathrm{C}}_3{\mathrm{H}}_8}+\underset{\mathrm{Oxygen}}{5{\mathrm{O}}_2}\to \underset{\mathrm{Carbon}\mathrm{dioxide}}{3{\mathrm{CO}}_2}+\underset{\mathrm{Water}}{4{\mathrm{H}}_2\mathrm{O}}$

Reactant Side	Product Side
$3$ Carbon atoms from ${\mathrm{C}}_3{\mathrm{H}}_8$	$3$ Carbon atom from ${\mathrm{CO}}_2$
$8$ Hydrogen atoms from ${\mathrm{C}}_3{\mathrm{H}}_8$	$2$ Hydrogen atoms from ${\mathrm{H}}_2\mathrm{O}$
$10$ Oxygen atoms from ${\mathrm{O}}_2$	$10$ Oxygen atoms, $6$ from ${\mathrm{CO}}_2$ and $4$ from ${\mathrm{H}}_2\mathrm{O}$

Step 5: Balanced chemical equation:-

• After each element has been balanced individually, the total amount of atoms of each element on the reactant and product sides are compared once more.
• The chemical equation is said to be balanced if there are no inequalities.
• Every element in this illustration now has the same amount of atoms on the reactant and product sides.
• Therefore, $\underset{\mathrm{Propane}}{{\mathrm{C}}_3{\mathrm{H}}_8}+\underset{\mathrm{Oxygen}}{5{\mathrm{O}}_2}\to \underset{\mathrm{Carbon}\mathrm{dioxide}}{3{\mathrm{CO}}_2}+\underset{\mathrm{Water}}{4{\mathrm{H}}_2\mathrm{O}}$ is a balanced chemical equation.