write balanced equations:
Sodium carbonate on reaction with hydrochloric acid in equal molar concentrations gives sodium chloride and sodium hydrogen carbonate.
Sodium hydrogen carbonate on reaction with hydrochloric acid gives sodium chloride, water and liberates Co2.
1) Na2CO3 + HCl ---> NaCl + NaHCO3
2) NaHCO3 + HCl --->NaCl + H2O + CO2
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