Like the similar-sounding compound sodium bicarbonate—baking soda—it's basic, and can react with acids. Two moles of hydrochloric acid and one mole of sodium carbonate form two moles of salt, one mole of carbon dioxide and one mole of water in an irreversible reaction. Sodium carbonate is more commonly known as washing soda. Sodium hydrogencarbonate is basic, and it reacts with the HCl still in solution to produce sodium chloride, carbon dioxide and water. NaHCO 3 (aq) + HCl(aq) → NaCl(aq) + CO 2 (g) + H 2 O(l) Phenolphthalein is a good indicator for the first reaction because it responds to the pH change caused by the formation of sodium hydrogencarbonate. The reaction for Na2CO3, sodium carbonate, and HCl, hydrochloric acid, is 2HCl + Na2CO3 -> 2NaCl + CO2 + H2O. HCl, or hydrochloric acid, is a strong acid that reacts with sodium carbonate. HCl, or hydrochloric acid, is a strong acid that reacts with sodium carbonate. Sodium carbonate, also known as soda ash and washing soda, is a naturally occurring base that takes the …