What gas is produced when sodium carbonate reacts with HNO3?

Answer 1

Carbon Dioxide (CO2) is the only gas produced in the reaction. The full reaction proceeds in two steps: first Nitric acid reacts with sodium carbonate to yield sodium nitrate and sodium bicarbonate. At this point the reaction would cease, but as long as there is excess Nitric acid the newly formed Sodium bicarbonate can be broken down further into another mole of sodium nitrate, water and gaseous Carbon dioxide (CO2) which mostly escapes the reaction quickly into the air, unless it is in a sealed airtight container, then it will remain in the liquid until opened like a can of cola! The two reactions are depicted below:

HNO3(aq) + Na2CO3(aq) --> NaNO3(aq) + NaHCO3(aq)

NaHCO3(aq) + HNO3(aq) --> NaNO3(aq) + H2O(l) + CO2(g)

Answer 2

Carbon dioxide is evolved.