The reaction between nitric acid (HNO₃) and potassium carbonate (K₂CO₃) is a double displacement reaction that produces carbon dioxide gas, water, and potassium nitrate.

Here's the balanced chemical equation:

2 HNO₃(aq) + K₂CO₃(aq) → 2 KNO₃(aq) + H₂O(l) + CO₂(g)

Explanation:

* Double displacement: The positive and negative ions of the reactants switch places. The hydrogen ions (H⁺) from nitric acid combine with the carbonate ions (CO₃²⁻) from potassium carbonate to form carbonic acid (H₂CO₃). The potassium ions (K⁺) from potassium carbonate combine with the nitrate ions (NO₃⁻) from nitric acid to form potassium nitrate (KNO₃).

* Gas evolution: Carbonic acid is unstable and quickly decomposes into water (H₂O) and carbon dioxide (CO₂) gas, which is released as bubbles.

Observations:

* You would observe fizzing or bubbling as carbon dioxide gas is released.

* The solution will likely become warm due to the exothermic nature of the reaction.

Important Note: This reaction is a neutralization reaction as an acid (HNO₃) reacts with a base (K₂CO₃). The reaction is also referred to as effervescence due to the release of carbon dioxide gas.