Which Salt Produces a Neutral Aqueous Solution?

To determine whether an aqueous solution of a salt is acidic, basic, or neutral, we must evaluate the origin of its ions. Specifically, we look at whether the cation or anion hydrolyzes (reacts with water) to produce H⁺ or OH⁻.

🧪 Analysis of Given Salts

1. NaF
Sodium (Na⁺) is a conjugate of a strong base (NaOH) → neutral
Fluoride (F⁻) is a conjugate base of a weak acid (HF) → hydrolyzes to produce OH⁻
➤ Overall: Basic solution

2. Ba(ClO₄)₂
Barium (Ba²⁺) is from a strong base (Ba(OH)₂) → neutral
Perchlorate (ClO₄⁻) is the conjugate base of a strong acid (HClO₄) → neutral
➤ Overall: Neutral solution ✅

3. RbNO₂
Rubidium (Rb⁺) from a strong base → neutral
Nitrite (NO₂⁻) is the conjugate base of weak acid HNO₂ → basic
➤ Overall: Basic solution

4. Rb₂CO₃
Rubidium (Rb⁺) → neutral
Carbonate (CO₃²⁻) is a weak base (from H₂CO₃) → hydrolyzes to OH⁻
➤ Overall: Basic solution

5. NH₄Cl
Ammonium (NH₄⁺) is the conjugate acid of a weak base (NH₃) → acidic
Chloride (Cl⁻) from strong acid HCl → neutral
➤ Overall: Acidic solution