Question

Balance this equation:
$Pb{\left( {N{O_3}} \right)_2} \to PbO + N{O_2} + {O_2}$

Answer 1

First we know the law of conservation of matter states that matter cannot be produced or destroyed in a closed isolated system.
To balance the chemical reaction, first consider the unbalanced equation to show the reactants and products. Then Identify and count the atoms in both the reactants and products in the following reaction. Then to make the number of atoms the same on both the reactants and products sides, we need to add coefficients so that the number of atoms of each element is the same on both sides of the chemical equation.

Complete answer:
Given unbalanced chemical equation is
$Pb{\left( {N{O_3}} \right)_2} \to PbO + N{O_2} + {O_2}$--(1)
In the equation (1), the number of $Pb$,$N$ atoms in the reactants and products are equal, but the number of oxygen atoms in the reactants and products are $6$ and $4$ respectively. So, multiply $PbO$ by $2$. Then the number of atoms $Pb$ in the reactants and products become $1$ and $2$ respectively. So, multiply $Pb{\left( {N{O_3}} \right)_2}$ and $N{O_2}$ by $2$. Then the number of oxygen atoms in the reactants and products becomes $12$ and $8$ respectively. So, we multiply ${O_2}$ by $3$.
Hence to balance the equation (1) we multiply $Pb{\left( {N{O_3}} \right)_2}$,$N{O_2}$ ,$PbO$ by $2$ and ${O_2}$ by $3$.
Then the balanced chemical equation is
$2Pb{\left( {N{O_3}} \right)_2} \to 2PbO + 2N{O_2} + 3{O_2}$.

Note:
Note that the coefficients in a balanced equation must be the simplest whole number ratio. Note that when balancing the number of any atom in the reactants and products we have to maintain that remaining atoms can be balanced. Chemical equation is a representation of a chemical reaction in terms of symbols and chemical formula of the reactants and products taking part in the reaction. The five basic types of chemical reactions are combination, decomposition, single-replacement, double-replacement, and combustion.