The reaction of barium carbonate (BaCO₃) and phosphoric acid (H₃PO₄) is a double displacement reaction that produces barium phosphate (Ba₃(PO₄)₂) and carbonic acid (H₂CO₃).

Here's the balanced chemical equation:

3BaCO₃(s) + 2H₃PO₄(aq) → Ba₃(PO₄)₂(s) + 3H₂CO₃(aq)

However, carbonic acid (H₂CO₃) is unstable and readily decomposes into carbon dioxide (CO₂) and water (H₂O):

H₂CO₃(aq) → CO₂(g) + H₂O(l)

Therefore, the overall reaction can be written as:

3BaCO₃(s) + 2H₃PO₄(aq) → Ba₃(PO₄)₂(s) + 3CO₂(g) + 3H₂O(l)

Explanation:

* Double Displacement: The barium (Ba²⁺) ions in barium carbonate switch places with the hydrogen (H⁺) ions in phosphoric acid.

* Solid Precipitate: Barium phosphate (Ba₃(PO₄)₂) is insoluble in water and forms a white solid precipitate.

* Gas Evolution: Carbonic acid decomposes, releasing carbon dioxide gas.

Observations:

You would observe:

* Formation of a white precipitate (Ba₃(PO₄)₂) at the bottom of the container.

* Effervescence (bubbling) due to the release of carbon dioxide gas.