Question

What is the equation for this reaction: Sodium bicarbonate and sulphuric acid react to form sodium sulphate, water, and carbon dioxide?

Answer 1

Hint : Here, we need to form a balanced equation for the given reaction. A balanced equation means that the number of atoms or molecules of every element should be equal on both sides i.e. before and after the reaction. Also the total charge on both sides of the equation should be the same.

Complete Step By Step Answer:
Let us mention the chemical formula for the reactants and the products of the reaction given above before starting the balancing.
Sodium Bicarbonate: $N{{a}^{+}}+HC{{O}_{3}}^{-}\to NaHC{{O}_{3}}$
Sulphuric Acid: $2{{H}^{+}}+S{{O}_{4}}^{-2}\to {{H}_{2}}S{{O}_{4}}$
Sodium Sulphate: $2N{{a}^{+}}+S{{O}_{4}}^{-2}\to N{{a}_{2}}S{{O}_{4}}$
Carbon dioxide: $C{{O}_{2}}$
Water: ${{H}_{2}}O$
Now, let us write the unbalanced equation in the form of reactants and products.
$NaHC{{O}_{3}}+{{H}_{2}}S{{O}_{4}}\to N{{a}_{2}}S{{O}_{4}}+C{{O}_{2}}+{{H}_{2}}O$
Now, let us start with the sodium ion. On the reactants side, there is one ion while on the product side, there are two ions. Hence, we will multiply with $2$ on the reactants side.
$\therefore 2NaHC{{O}_{3}}+{{H}_{2}}S{{O}_{4}}\to N{{a}_{2}}S{{O}_{4}}+C{{O}_{2}}+{{H}_{2}}O$
Now, let us consider carbon elements. On the reactants side, there are two atoms while on the products side there is only one. Hence, we will multiply with $2$ on the product side.
$\therefore 2NaHC{{O}_{3}}+{{H}_{2}}S{{O}_{4}}\to N{{a}_{2}}S{{O}_{4}}+2C{{O}_{2}}+{{H}_{2}}O$
Now, considering hydrogen, we get 4 atoms on the reactants side and only two on the products side. Hence multiplying $2$ on the product side.
$\therefore 2NaHC{{O}_{3}}+{{H}_{2}}S{{O}_{4}}\to N{{a}_{2}}S{{O}_{4}}+2C{{O}_{2}}+2{{H}_{2}}O$
Now, if we check oxygen, it is automatically balanced.
Thus, this is the balanced equation for the given reaction.

Note :
To form a balanced equation, we should always start with the atom or molecule that is least involved in the reaction and whose valency before and after the reaction is same i.e. spectator ions that just get detached from one molecule and gets attached to another molecule without changing any bonds. The elements like hydrogen and oxygen mostly, that are most involved in the reaction and change their bonds with elements should be checked at the end.