Dissociated

Definition

Dissociated refers to the process by which a molecule or ion separates into two or more smaller, electrically charged particles called ions. This is a key concept in understanding the behavior of biological acids and the Henderson-Hasselbalch equation, which describes the relationship between the pH of a solution and the concentrations of the dissociated and undissociated forms of an acid.

5 Must Know Facts For Your Next Test

1. Dissociation is the process by which a molecule or ion separates into two or more smaller, electrically charged particles called ions.
2. The degree of dissociation of an acid is determined by its acid dissociation constant (Ka), which is a measure of the acid's strength.
3. Strong acids, such as hydrochloric acid (HCl), are highly dissociated in aqueous solutions, meaning they readily donate hydrogen ions (H+) to the solution.
4. Weak acids, such as acetic acid (CH3COOH), are only partially dissociated in aqueous solutions, with a balance between the dissociated and undissociated forms.
5. The Henderson-Hasselbalch equation is used to describe the relationship between the pH of a solution and the concentrations of the dissociated and undissociated forms of an acid or base.

Review Questions

• Explain the concept of dissociation and its importance in the context of biological acids.
  • Dissociation is the process by which a molecule or ion separates into two or more smaller, electrically charged particles called ions. In the context of biological acids, dissociation is a crucial concept because it determines the behavior and properties of these acids in aqueous solutions. The degree of dissociation of an acid is measured by its acid dissociation constant (Ka), which reflects the acid's strength. Strong acids, such as hydrochloric acid (HCl), are highly dissociated, meaning they readily donate hydrogen ions (H+) to the solution, while weak acids, such as acetic acid (CH3COOH), are only partially dissociated, with a balance between the dissociated and undissociated forms. Understanding the concept of dissociation is essential for predicting the pH of a solution and the relative concentrations of the dissociated and undissociated forms of an acid, which is crucial in many biological processes.
• Describe the relationship between the degree of dissociation and the acid dissociation constant (Ka) of a biological acid.
  • The degree of dissociation of a biological acid is directly related to its acid dissociation constant (Ka). The acid dissociation constant is a measure of the strength of an acid, representing the equilibrium between the dissociated and undissociated forms of the acid in an aqueous solution. Strong acids, such as hydrochloric acid (HCl), have a high Ka value, indicating that they are highly dissociated in aqueous solutions, meaning they readily donate hydrogen ions (H+) to the solution. Conversely, weak acids, such as acetic acid (CH3COOH), have a low Ka value, indicating that they are only partially dissociated, with a balance between the dissociated and undissociated forms. The degree of dissociation of an acid is a crucial factor in determining the pH of a solution and the relative concentrations of the dissociated and undissociated forms of the acid, which is essential in understanding many biological processes.
• Explain how the concept of dissociation is applied in the Henderson-Hasselbalch equation and its importance in the context of biological acids.
  • The concept of dissociation is central to the Henderson-Hasselbalch equation, which describes the relationship between the pH of a solution and the concentrations of the dissociated and undissociated forms of an acid or base. The Henderson-Hasselbalch equation relies on the degree of dissociation of the acid, as represented by its acid dissociation constant (Ka). The equation allows for the calculation of the pH of a solution based on the relative concentrations of the dissociated and undissociated forms of the acid. This is crucial in the context of biological acids, as the pH of a solution can significantly impact the behavior and function of biological molecules and processes. Understanding the concept of dissociation and how it is applied in the Henderson-Hasselbalch equation is essential for predicting the pH of biological systems and for analyzing the equilibrium between the dissociated and undissociated forms of an acid, which is vital in many areas of biochemistry and physiology.

Related terms

Acid Dissociation Constant (Ka): The acid dissociation constant is a measure of the strength of an acid, representing the equilibrium between the dissociated and undissociated forms of the acid in an aqueous solution.

pH:

pH is a measure of the acidity or basicity of a solution, based on the concentration of hydrogen ions (H+) present.

Henderson-Hasselbalch Equation:

The Henderson-Hasselbalch equation is a mathematical expression that relates the pH of a solution to the concentrations of the dissociated and undissociated forms of an acid or base.