Is the pH greater than, equal to, or less than 7 after the neutralization of each of the following pairs of acids and bases?(c) HBr and aniline (C6H5NH2)

Verified step by step guidance

1. Identify the nature of the acid and base involved in the reaction. HBr is a strong acid, and aniline (C6H5NH2) is a weak base.
2. Write the balanced chemical equation for the neutralization reaction: HBr + C6H5NH2 \rightarrow C6H5NH3^+ + Br^-.
3. Determine the products of the reaction. The reaction forms the anilinium ion (C6H5NH3^+) and bromide ion (Br^-).
4. Consider the properties of the conjugate acid formed. The anilinium ion (C6H5NH3^+) is a weak acid, which can slightly dissociate in water, contributing to the acidity of the solution.
5. Conclude the pH of the solution. Since the strong acid (HBr) completely neutralizes the weak base (aniline), the resulting solution will be slightly acidic, meaning the pH will be less than 7.

Key Concepts

Neutralization Reaction

A neutralization reaction occurs when an acid reacts with a base to produce water and a salt. In this process, the acidic properties of the acid and the basic properties of the base are neutralized, typically resulting in a solution that is closer to neutral pH, which is 7. The specific pH of the resulting solution depends on the strength of the acid and base involved.

Strong vs. Weak Acids and Bases

Acids and bases can be classified as strong or weak based on their ability to dissociate in water. Strong acids, like HBr, completely dissociate into ions, while weak bases, like aniline, only partially dissociate. This distinction is crucial in predicting the pH of the solution after neutralization, as the strength of the acid and base will influence the final pH.

pH Scale

The pH scale measures the acidity or basicity of a solution, ranging from 0 to 14. A pH of 7 is considered neutral, below 7 is acidic, and above 7 is basic. Understanding the pH scale is essential for determining the outcome of a neutralization reaction, as it helps to assess whether the resulting solution is acidic, neutral, or basic based on the properties of the reactants.