Formation of NaHCO3 by the reaction of Na2CO3 and HCl:

When Na2CO3 reacts with HCl, a double displacement reaction takes place, which can be represented by the following chemical equation:

Na2CO3 + 2HCl → 2NaCl + H2CO3

In this reaction, Na2CO3 (sodium carbonate) reacts with HCl (hydrochloric acid) to produce NaCl (sodium chloride) and H2CO3 (carbonic acid).

However, carbonic acid is a very unstable compound and decomposes immediately into water and carbon dioxide.

H2CO3 → H2O + CO2

Thus, the net reaction can be represented as:

Na2CO3 + 2HCl → 2NaCl + H2O + CO2

The carbon dioxide gas produced in this reaction reacts with water to form carbonic acid, which then reacts with the remaining HCl to produce more carbon dioxide gas.

H2O + CO2 → H2CO3

HCl + H2CO3 → CO2 + H2O + Cl-

The final product of this reaction is NaCl and carbon dioxide gas, which reacts with water to form a small amount of carbonic acid.

2NaCl + CO2 + H2O → Na2CO3 + 2HCl

The carbonic acid then decomposes into water and carbon dioxide gas, which escapes into the atmosphere.

Overall, the reaction can be summarized as:

Na2CO3 + 2HCl → 2NaCl + CO2 + H2O + heat

Thus, NaHCO3 is formed by the reaction of Na2CO3 and HCl, as a result of the decomposition of carbonic acid formed in the reaction.

A)NaOH + H2CO3 is correct as NaHCO3 is only formed by the displacement reaction of Sodium Hydroxide and Bi-carbonate.