Question

Write the balanced chemical equations for the reactions.
Sodium carbonate on reaction with hydrochloric acid in equal molar concentrations gives sodium chloride and sodium hydrogen carbonate.
a.) $N{{a}_{2}}C{{O}_{3}}+2HCl\to NaCl+2NaHC{{O}_{3}}$
b.) $2N{{a}_{2}}C{{O}_{3}}+HCl\to 2NaCl+NaHC{{O}_{3}}$
c.) $3N{{a}_{2}}C{{O}_{3}}+HCl\to NaCl+2NaHC{{O}_{3}}$
d.) $N{{a}_{2}}C{{O}_{3}}+HCl\to NaCl+NaHC{{O}_{3}}$

Answer 1

Hint: To write a balanced chemical equation first balance the atoms other than oxygen and hydrogen on both the sides of the reaction. Then balance the oxygen atoms. Later balance the hydrogen atoms and recheck whether all the atoms are balanced or not on both sides of the reaction.

Complete step by step answer:
Given that Sodium carbonate on reaction with hydrochloric acid in equal molar concentrations gives sodium chloride and sodium hydrogen carbonate. The reaction will be as follows:
$N{{a}_{2}}C{{O}_{3}}+HCl\to NaCl+NaHC{{O}_{3}}$

In the above reaction we just wrote the reactants and the products that took place in the chemical reaction without writing any stoichiometry. Now try to balance the equation,
First try to balance the atoms other than oxygen and hydrogen atoms.

Balancing the sodium on both sides of the reaction:
$N{{a}_{2}}C{{O}_{3}}+HCl\to NaCl+NaHC{{O}_{3}}$
We were having 2 sodium atoms on the reactant side and 2 sodium atoms on the product side, so the sodium atoms are balanced.

Balancing the carbon on both sides of the reaction:
$N{{a}_{2}}C{{O}_{3}}+HCl\to NaCl+NaHC{{O}_{3}}$
We were having 1 carbon atom on the reactant side and 1 carbon atoms on the product side, so the carbon atoms are balanced.

Balancing the chlorine on both sides of the reaction:
$N{{a}_{2}}C{{O}_{3}}+HCl\to NaCl+NaHC{{O}_{3}}$
We were having 1 chlorine atom on the reactant side and 1 chlorine atoms on the product side, so the chlorine atoms are balanced.

Balancing the oxygen on both sides of the reaction and then hydrogen atoms:
$N{{a}_{2}}C{{O}_{3}}+HCl\to NaCl+NaHC{{O}_{3}}$
We were having 3 oxygen atoms on the reactant side and 3 oxygen atoms on the product side, so the oxygen atoms are balanced.
We were having 1 hydrogen atoms on the reactant side and 1 hydrogen atoms on the product side, so the hydrogen atoms are balanced.

Now all the atoms are balanced. The required balanced chemical equation is :
$N{{a}_{2}}C{{O}_{3}}+HCl\to NaCl+NaHC{{O}_{3}}$
So, the correct answer is “Option D”.

Note: In each step of balancing the atoms, also check the previous balanced atom whether it remains same (balanced) or changed (unbalanced) and accordingly we should go in such a way that all the atoms (which are balanced in the previous steps) should be balanced along with the currently balancing atom. And after going through all the steps once again check if the whole reaction is balanced or not because while balancing an atom the balance of another atom may disturb.