Question

Balance the given reaction.
$S + HN{O_3} \to {H_2}S{O_4} + N{O_2} + {H_2}O$

Answer 1

A chemical reaction refers to a phenomenon which leads to the chemical transition of one type of chemical substance to another. Chemical reactions involve changes with reference to the electrons positioning in the formation as well as decomposition of chemical bonds that exist between the atoms, while no change occurs to the nuclei i.e. no alteration to the elements present.

Complete step by step solution:
Unbalanced chemical equations possess different numbers of atoms of distinct elements in reactants as well as products. On the other hand, balanced chemical equations possess the same number of atoms of distinct elements in reactants as well as products. It should be noted that the same masses of different elements should be present in reactants and products while balancing the chemical equation. The unbalanced chemical reaction given in the question is stated below:
$S + HN{O_3} \to {H_2}S{O_4} + N{O_2} + {H_2}O$
We will equalise the number of atoms of elements on both sides while balancing the given reaction equation. We will balance the number of atoms by multiplying $HN{O_3}$ with coefficient 6 and $N{O_2}$ with 6 while ${H_2}O$ will be multiplied with 2 as listed below:

Reactants/products	No. of moles in Unbalanced equation	No. of moles in Balanced equation
$S$	1	1
$HN{O_3}$	1	$1 \times 6 = 6$
${H_2}S{O_4}$	1	1
$N{O_2}$	1	$1 \times 6 = 6$
${H_2}O$	1	$1 \times 2 = 2$

So now, the number of atoms will become equal on both sides as listed below:

Name of atoms	Number of atoms in Unbalanced equation	Number of atoms in Balanced equation
Left side	Right side	Left side
$S$	1	1
$H$	1	4
$O$	3	7
$N$	1	1

The final balanced reaction is depicted below:
$S + 6HN{O_3} \to {H_2}S{O_4} + 6N{O_2} + 2{H_2}O$

Note:
A balanced chemical equation simply obeys the law of conservation of mass. Balancing the chemical equations is a significant guiding principle in chemistry. As the given reaction in question is a redox reaction, oxidation number method can also be used to balance it. This method works on the principle that the amount of oxidation equals the amount of reduction in the whole chemical reaction.