Is NaBrO4 (Sodium Perbromate): 1. Ionic or Molecular? and 2. Acid, Base, or neither?
The correct answer and explanation is:
Is Sodium Perbromate (NaBrO₄):
- Ionic or Molecular?
Sodium perbromate (NaBrO₄) is an ionic compound. It consists of the sodium cation (Na⁺) and the perbromate anion (BrO₄⁻). The electrostatic attraction between these oppositely charged ions forms the ionic bond. Sodium, a metal, readily loses one electron to form the Na⁺ ion, while the perbromate ion, a polyatomic anion containing bromine in the +7 oxidation state, is formed when bromine bonds with four oxygen atoms, collectively gaining an overall -1 charge. - Acid, Base, or Neither?
Sodium perbromate is neither an acid nor a base; it is a neutral salt. This classification is based on its behavior in aqueous solution:- Acids release hydrogen ions (H⁺) in solution, which NaBrO₄ does not.
- Bases release hydroxide ions (OH⁻) in solution, which NaBrO₄ also does not.
- Instead, NaBrO₄ dissociates into Na⁺ and BrO₄⁻ ions in water. The Na⁺ cation does not affect the solution’s pH because it is a spectator ion, and BrO₄⁻ is derived from perbromic acid (HBrO₄), which is a strong acid. Consequently, BrO₄⁻ is a very weak conjugate base and does not hydrolyze to affect the pH.
Explanation
Sodium perbromate’s neutrality stems from the nature of its constituent ions. The strong acidity of its parent acid, HBrO₄, ensures that BrO₄⁻ has negligible basicity, and the solution remains neutral. Ionic compounds like NaBrO₄ are salts that result from the neutralization of a strong acid and a strong base, making their aqueous solutions typically neutral. Thus, while it is clearly ionic, it does not fit the criteria for being an acid or a base.