Ba(OH)₂ (aq) + H₂CO₃ (aq) → BaCO₃ (s) + 2 H₂O (l)
Here's what happens:
* Barium hydroxide (Ba(OH)₂) is a strong base: It readily dissociates in water to form barium ions (Ba²⁺) and hydroxide ions (OH⁻).
* Carbonic acid (H₂CO₃) is a weak acid: It partially dissociates in water to form hydrogen ions (H⁺) and bicarbonate ions (HCO₃⁻).
* Neutralization: The hydroxide ions from barium hydroxide react with the hydrogen ions from carbonic acid, forming water (H₂O).
* Salt formation: The barium ions (Ba²⁺) from barium hydroxide combine with the carbonate ions (CO₃²⁻) from carbonic acid to form barium carbonate (BaCO₃), which is an insoluble solid (precipitate).
Key points:
* The reaction is exothermic, meaning it releases heat.
* The precipitate of barium carbonate is white and can be observed as a solid forming in the solution.
* Carbonic acid is unstable and easily decomposes into carbon dioxide (CO₂) and water. This decomposition can be observed as effervescence (bubbling) in the reaction mixture.
This reaction is a fundamental example of acid-base chemistry and is used in various applications, including the production of barium carbonate, which is used in paint pigments, ceramics, and glassmaking.
