Determine if each salt will form a solution that is acidic, basic, or pH-neutral. a. Al(NO₃)₃

Verified step by step guidance

1. Identify the ions formed when Al(NO_3)_3 dissolves in water: Al^{3+} and NO_3^-.
2. Determine the nature of the cation: Al^{3+} is a small, highly charged metal ion, which can hydrolyze water to form H^+ ions, making the solution acidic.
3. Determine the nature of the anion: NO_3^- is the conjugate base of a strong acid (HNO_3), and it does not affect the pH of the solution.
4. Combine the effects of the cation and anion: Since Al^{3+} can make the solution acidic and NO_3^- is neutral, the overall solution will be acidic.
5. Conclude that the solution of Al(NO_3)_3 in water will be acidic due to the hydrolysis of Al^{3+}.

Key Concepts

Salt Hydrolysis

Salt hydrolysis is the reaction of a salt with water, leading to the formation of acidic or basic solutions. When a salt dissolves in water, its constituent ions can interact with water molecules, potentially altering the pH of the solution. The nature of the ions—whether they are derived from a strong or weak acid/base—determines if the solution will be acidic, basic, or neutral.

Acidic and Basic Ions

Acidic ions are typically derived from weak acids and can donate protons (H+) to water, lowering the pH. Conversely, basic ions come from weak bases and can accept protons, raising the pH. In the case of Al(NO3)3, the aluminum ion (Al3+) can hydrolyze to produce H+ ions, indicating that the solution will be acidic.

pH Scale

The pH scale measures the acidity or basicity of a solution, ranging from 0 (very acidic) to 14 (very basic), with 7 being neutral. A pH less than 7 indicates an acidic solution, while a pH greater than 7 indicates a basic solution. Understanding the pH scale is essential for determining the nature of the solution formed by the dissolution of salts like Al(NO3)3.