CH₃COOH/CH₃COO⁻

Definition

CH₃COOH, known as acetic acid, is a weak acid that partially dissociates in solution to form CH₃COO⁻, the acetate ion. This pair represents a classic example of an acid-base conjugate pair in the Brønsted-Lowry theory, where acetic acid donates a proton (H⁺) to become acetate, illustrating the dynamic relationship between acids and their corresponding conjugate bases.

5 Must Know Facts For Your Next Test

1. Acetic acid is commonly found in vinegar and is responsible for its sour taste.
2. In solution, acetic acid exists in equilibrium with its ions, where the extent of dissociation can be quantified using the acid dissociation constant (Kₐ).
3. The acetate ion (CH₃COO⁻) can act as a base by accepting a proton to reform acetic acid.
4. The equilibrium between CH₃COOH and CH₃COO⁻ is essential for buffering solutions, helping to maintain pH levels in biological systems.
5. Acetic acid and acetate ion play significant roles in various biochemical processes, including metabolism and cellular respiration.

Review Questions

• How does the dissociation of acetic acid into acetate illustrate the principles of the Brønsted-Lowry theory?
  • The dissociation of acetic acid (CH₃COOH) into acetate (CH₃COO⁻) exemplifies the Brønsted-Lowry theory by demonstrating how acetic acid acts as a proton donor. When CH₃COOH donates a proton (H⁺), it transforms into its conjugate base, CH₃COO⁻. This interaction highlights the dynamic nature of acid-base chemistry, where acids and their conjugate bases are interrelated through proton transfer.
• Discuss the significance of the equilibrium established between acetic acid and acetate in terms of pH stability in biological systems.
  • The equilibrium between acetic acid and acetate is crucial for maintaining pH stability in biological systems, as it allows for effective buffering. When there is an excess of hydrogen ions (H⁺) in a solution, acetate can accept these protons, minimizing pH changes. Conversely, if there is a deficit of H⁺ ions, acetic acid can release protons to restore balance. This balance is vital for many biochemical processes that are sensitive to pH fluctuations.
• Evaluate the role of acetic acid and its conjugate base in metabolic pathways and how this reflects on their importance in biochemistry.
  • Acetic acid and its conjugate base, acetate, are integral to several metabolic pathways, including the citric acid cycle and fatty acid metabolism. Acetate serves as an important building block for synthesizing lipids and other biomolecules. By acting both as an acid and as a base, they facilitate essential biochemical reactions while helping to regulate pH levels within cells. This dual functionality underscores their significance in maintaining homeostasis and supporting energy production within living organisms.

Related terms

Brønsted-Lowry Acid: A substance that donates a proton (H⁺) in a chemical reaction.

Brønsted-Lowry Base:

A substance that accepts a proton (H⁺) in a chemical reaction.

Equilibrium:

The state in which the rates of the forward and reverse reactions are equal, resulting in constant concentrations of reactants and products.