Write a balanced, net-ionic equation for the reaction of aqueous solutions of hydrochloric acid (HCl) and sodium carbonate (Na2CO3). a. 2 HCl(aq) + Na2CO3(aq) → H2CO3(aq) + 2 NaCl(aq) b. 2 H+(aq) + CO32-(aq) → H2CO3(aq) c. H+(aq) + NaCO3-(aq) → NaHCO3(s) d. 2 H+(aq) + CO32-(aq) → H2O + CO2(g) e. Cl-(aq) + Na+(aq) → NaCl(aq)
The Correct Answer and Explanation is:
To determine the correct net ionic equation for the reaction of aqueous solutions of hydrochloric acid (HCl) and sodium carbonate (Na2CO3), we need to consider the chemical interactions between the ions in solution.
Step-by-step analysis:
- Write the full ionic equation:
- When HCl dissociates in water, it breaks into H⁺ (aq) and Cl⁻ (aq).
- Sodium carbonate (Na₂CO₃) dissociates into 2 Na⁺ (aq) and CO₃²⁻ (aq).
- The reaction between H⁺ and CO₃²⁻ (carbonate ion) forms carbonic acid (H₂CO₃), which is unstable and rapidly decomposes into water (H₂O) and carbon dioxide (CO₂) gas.
- Write the net ionic equation:
The full ionic equation includes spectator ions like Na⁺ and Cl⁻, which do not participate in the reaction. We remove them to get the net ionic equation. The final net ionic equation becomes: 2H+(aq)+CO32−(aq)→H2O(l)+CO2(g)2 H^+(aq) + CO_3^{2-}(aq) \rightarrow H_2O(l) + CO_2(g)2H+(aq)+CO32−(aq)→H2O(l)+CO2(g) This shows that the hydrogen ions from hydrochloric acid react with the carbonate ions from sodium carbonate to form water and carbon dioxide gas.
Option analysis:
- Option a (2 HCl(aq) + Na₂CO₃(aq) → H₂CO₃(aq) + 2 NaCl(aq)): This is the molecular equation but does not show the actual ionization and reaction of the acid with the carbonate.
- Option b (2 H⁺(aq) + CO₃²⁻(aq) → H₂CO₃(aq)): This is part of the reaction but neglects the decomposition of carbonic acid into water and carbon dioxide.
- Option c (H⁺(aq) + NaCO₃⁻(aq) → NaHCO₃(s)): This does not represent the carbonate ion properly and incorrectly implies the formation of sodium bicarbonate (NaHCO₃) instead of CO₂.
- Option d (2 H⁺(aq) + CO₃²⁻(aq) → H₂O + CO₂(g)): This is the correct net ionic equation, as it properly shows the complete reaction where carbonic acid decomposes.
- Option e (Cl⁻(aq) + Na⁺(aq) → NaCl(aq)): This shows the spectator ions, which do not participate in the reaction and are thus not part of the net ionic equation.
Conclusion:
The correct answer is Option d: 2H+(aq)+CO32−(aq)→H2O(l)+CO2(g)2 H^+(aq) + CO_3^{2-}(aq) \rightarrow H_2O(l) + CO_2(g)2H+(aq)+CO32−(aq)→H2O(l)+CO2(g)
This equation reflects the neutralization of carbonate ions with hydrogen ions to produce water and carbon dioxide.
