Solubility of CH₃COOH decreases in presence of CH₃COONa due to:

The correct answer is Common Ion Effect.

Key Points

• Common ion effect occurs when a solution already contains ions that are present in the solute being added, reducing the solubility of the solute due to ion interference.
• In the case of CH₃COOH, the addition of CH₃COONa introduces acetate ions (CH₃COO⁻), which are common to both the acid and the salt.
• The presence of acetate ions shifts the dissociation equilibrium of CH₃COOH to the left, decreasing the concentration of hydrogen ions and reducing its solubility.
• This phenomenon is explained by Le Chatelier's Principle, where the equilibrium adjusts to counter the increase in concentration of common ions.
• The common ion effect is a key concept in acid-base chemistry, particularly in buffer solutions and solubility equilibria.

Additional Information

• Le Chatelier's Principle:
  • This principle states that if a dynamic equilibrium is disturbed by changing conditions, the position of equilibrium shifts to counteract the change.
  • In the case of the common ion effect, the equilibrium adjusts to reduce the concentration of the added common ion.
• Buffer Solutions:
  • Buffers are solutions that resist changes in pH upon the addition of small amounts of acid or base.
  • The common ion effect plays a crucial role in maintaining the pH stability of buffers.
• Applications of Common Ion Effect:
  • Used in analytical chemistry for selective precipitation of ions.
  • Helps in controlling the solubility of compounds in pharmaceutical formulations.
  • Important in maintaining pH stability in biological systems.
• Solubility Equilibrium:
  • Describes the balance between dissolved ions and undissolved solid in a saturated solution.
  • The common ion effect influences solubility equilibrium by altering the ionic concentrations.