Answer:
Standard acid-base reaction in two stages:
Na2CO3 + HCl → NaHCO3 +NaCl
NaHCO3 + HCl → NaCl + CO2 + H2O
If only a small quantity of acid is added (and the overall solution remains above pH 7), the reaction would stop at stage 1 and you’d be left with an aqueous solution of sodium chloride and sodium bicarbonate. Adding more acid would lead to the bicarbonate being converted to carbon dioxide and water, with the CO2 coming out of solution as a gas and more sodium chloride being produced.
