What happens when a strong acid such as HBr is dissolved in water?

Verified step by step guidance

1. Identify that HBr is a strong acid, which means it completely dissociates in water.
2. Write the chemical equation for the dissociation of HBr in water: \( \text{HBr} \rightarrow \text{H}^+ + \text{Br}^- \).
3. Recognize that the \( \text{H}^+ \) ions increase the concentration of hydrogen ions in the solution, making it acidic.
4. Understand that the \( \text{Br}^- \) ions are spectator ions and do not affect the acidity of the solution.
5. Conclude that the solution becomes acidic due to the presence of \( \text{H}^+ \) ions, which can be measured by a decrease in pH.

Key Concepts

Dissociation of Acids

When a strong acid like HBr is dissolved in water, it completely dissociates into its constituent ions. This means that HBr separates into hydrogen ions (H⁺) and bromide ions (Br⁻), resulting in a solution that has a high concentration of H⁺ ions, which is responsible for the acidic properties of the solution.

pH Scale

The pH scale measures the acidity or basicity of a solution, ranging from 0 to 14. A pH less than 7 indicates an acidic solution, with lower values representing stronger acids. When HBr is dissolved in water, the increase in H⁺ ions lowers the pH, making the solution highly acidic, often close to 0 for concentrated solutions.

Ionization in Water

Ionization refers to the process by which molecules break apart into ions in a solvent, such as water. In the case of HBr, the strong acid ionizes completely, meaning that all of the HBr molecules convert into H⁺ and Br⁻ ions. This complete ionization is a characteristic feature of strong acids, distinguishing them from weak acids, which only partially ionize.