Question

Write the balanced chemical equations for the following reactions:
Sodium hydrogen carbonate on reaction with hydrochloric acid gives sodium chloride, water and liberates carbon dioxide.
A. $$NaHC{O}_3+2HCl\to NaCl+2H_{2}O+C{O}_2$$
B. $$2NaHC{O}_3+2HCl\to NaCl+H_{2}O+2C{O}_2$$
C. $$NaHC{O}_3+HCl\to NaCl+H_{2}O+C{O}_2$$
D. $$2NaHC{O}_3+2HCl\to 2NaCl+H_{2}O+C{O}_2$$

Answer 1

Hint: To solve this question, use the law of conservation of mass. Use hit and trial method to balance the number of atoms on both sides.

Complete step by step answer:
Let us solve this question by understanding a chemical equation and the law of conservation of mass.
“A chemical equation shows us the substances involved in a chemical reaction - the substances that react (reactants) and the substances that are produced (products)”.
“The law of conservation of mass states that mass in an isolated system is neither created nor destroyed by chemical reactions or physical transformations. According to the law of conservation of mass, the mass of the products in a chemical reaction must equal the mass of the reactants”.
According to the question, we’ve been given

Reactants –
Sodium hydrogen carbonate
Hydrochloric acid

Products –
Sodium chloride
Water
Carbon dioxide

Now, we need to balance the number of atoms on the reactants and products side of the reaction.
Let us write the equation first.
$$NaHC{O}_3+HCl\to NaCl+H_{2}O+C{O}_2$$
Let us balance elements on both sides –

As we can see, the number of elements both reactants and products are balanced.
Therefore, the answer is – option (c) – $$NaHC{O}_3+HCl\to NaCl+H_{2}O+C{O}_2$$.

Note: Example of law of conservation of mass –
Combustion process: burning of wood follows conservation of mass since the burning of wood involves Oxygen, Carbon dioxide, water vapor and ashes. The elements in reactants and products are balanced.