Question

Balance the following chemical equations?

${\mathrm{NaNO}}_3+{\mathrm{H}}_2{\mathrm{SO}}_4\to {\mathrm{Na}}_2{\mathrm{SO}}_4+{\mathrm{HNO}}_3$

Answer 1

The major steps involved in balancing a chemical equation are as follows:-

1. Write the chemical equation in the form of a word equation. Keep the reactants on the left side and the products on the right side. Separate them by an arrow$\left(\to \right)$, whose head points from the reactants towards the products.
2. Convert the word equation into the symbol equation by writing the symbols and formulae of all the reactants and products.
3. Make the atoms of different elements on both sides of the equation equal by a suitable method. This is known as the balancing of equations.
4. Do not change the formulae of the substances while balancing the equation.
5. Make the equation more informative if possible.

${\mathrm{NaNO}}_3+{\mathrm{H}}_2{\mathrm{SO}}_4\to {\mathrm{Na}}_2{\mathrm{SO}}_4+{\mathrm{HNO}}_3$

The balancing of the equations is done in the following steps :
(i) Let us count the number of atoms of all the elements in the reactants and products on both sides of the equation.

Element/Ion	No. of atoms of reactants(L.H.S)	No. of atoms of products(R.H.S)
Na	1	2
NO3	1	1
H	2	1
SO4	1	1

Thus, the number of ‘$\left({\mathrm{NO}}_3\right)$’ and ‘$\left({\mathrm{SO}}_4\right)$’ ions are equal on both sides. At the same time, the number of ‘Na’ atom and ‘H’ atom are not equal.

(ii) On inspection, to balance the atoms, put coefficient 2 before $\left({\mathrm{NaNO}}_3\right)$ on the reactant side and 2 before $\left({\mathrm{HNO}}_3\right)$ on the product side.

The partially balanced equation may be written as $2{\mathrm{NaNO}}_3+{\mathrm{H}}_2{\mathrm{SO}}_4\to {\mathrm{Na}}_2{\mathrm{SO}}_4+2{\mathrm{HNO}}_3$

(iii) On final inspection, the number of atoms of all the elements on both sides of the equation is equal. Therefore, the equation is balanced.

$\underset{\mathrm{Sodium}\mathrm{Nitrate}}{2{\mathrm{NaNO}}_3\left(\mathrm{s}\right)}+\underset{\mathrm{Sulfuric}\mathrm{acid}}{{\mathrm{H}}_2{\mathrm{SO}}_4(\mathrm{aq}.)}\to \underset{\mathrm{Sodium}\mathrm{Sulfate}}{{\mathrm{Na}}_2{\mathrm{SO}}_4(\mathrm{aq}.)}+\underset{\mathrm{Nitric}\mathrm{acid}}{2{\mathrm{HNO}}_3(\mathrm{aq}.)}$