Which is the correct net ionic equation for the reaction of acetic acid with potassium hydroxide? HC2H3O2 + KOH = H2O + KC2H3O2 Which of the following is the correct net ionic equation for the addition of aqueous ammonia to precipitate silver chloride? AgCl + 2NH3 = [Ag(NH3)2]+ + Cl- Potassium metal reacts with water to release gas and potassium compound. Which of the following statements is false? The solution is acidic. The gas is hydrogen.
The Correct Answer and Explanation is:
Let’s break this down question by question and identify the correct answers with detailed explanations.
1. Net Ionic Equation for Acetic Acid and Potassium Hydroxide:
Given:
HC₂H₃O₂ (acetic acid) + KOH → H₂O + KC₂H₃O₂
Correct Net Ionic Equation:
HC₂H₃O₂ (aq) + OH⁻ (aq) → H₂O (l) + C₂H₃O₂⁻ (aq)
Explanation:
Potassium hydroxide (KOH) is a strong base, which dissociates completely in water into K⁺ and OH⁻ ions.
Acetic acid (HC₂H₃O₂) is a weak acid, so it does not dissociate fully.
In a neutralization reaction, the hydrogen ion from the acid reacts with the hydroxide ion from the base to form water.
The acetate ion (C₂H₃O₂⁻) remains in solution.
K⁺ is a spectator ion, so it is left out of the net ionic equation.
2. Net Ionic Equation for Silver Chloride and Ammonia:
Given Reaction:
AgCl + 2NH₃ → [Ag(NH₃)₂]⁺ + Cl⁻
Correct Net Ionic Equation:
AgCl (s) + 2NH₃ (aq) → [Ag(NH₃)₂]⁺ (aq) + Cl⁻ (aq)
Explanation:
Silver chloride (AgCl) is an insoluble salt, so it exists as a solid.
When aqueous ammonia (NH₃) is added, it acts as a ligand and forms a soluble complex ion, [Ag(NH₃)₂]⁺.
This causes AgCl to dissolve.
The chloride ion is released into solution.
This is a classic complex ion formation reaction, commonly used to distinguish silver ions in qualitative analysis.
3. Potassium Metal Reacts with Water:
Reaction:
2K (s) + 2H₂O (l) → 2KOH (aq) + H₂ (g)
True Statements:
- The gas released is hydrogen. ✅
- The potassium compound formed is potassium hydroxide. ✅
False Statement:
“The solution is acidic.” ❌
Explanation:
The correct statement is that the solution is basic, not acidic.
Potassium hydroxide (KOH) is a strong base, and its formation raises the pH of the solution.
Hydrogen gas is released due to the displacement of hydrogen from water by the reactive potassium metal.
Therefore, the false statement is the claim that the solution is acidic.
Summary of Correct Answers:
- HC₂H₃O₂ + OH⁻ → H₂O + C₂H₃O₂⁻
- AgCl + 2NH₃ → [Ag(NH₃)₂]⁺ + Cl⁻
- False statement: “The solution is acidic.”
