Acetic acid is already quite soluble in water. Benzoic acid is less soluble and

Question

Acetic acid is already quite soluble in water. Benzoic acid is less soluble and naphthoic acid is hardly soluble in water. Give an explanation for this trend in terms of INTERMOLECULAR FORCES. The important intermolecular forces that explain this are between the SOLVENT MOLECUELS THEMSELVES, not so much between the solute molecules or between the solute and solvent molecules, therefore you only need to talk about those between the solvent molecules. brief explanation should include the word energy.

Explanation / Answer

Note, COOH gr is common to all the three acids, They are soluble or partially soluble in water because of H bonding interactions between the cooh gr of the acids and the water molecules.

however, between these there acids, hydrophilicity order is: acetic acid > Benzoic acid > naphthoic acid

we know the pricipal that ."like dissolves like"; water is highly hydrophilic, so it likes acetic acid more than the others, providing highest solubility for acetic acid.

in naphthoic acid, contribution of the hydrophobic part is quite larger in relative to the hydrophilic cooh gr. therefore, the hydrophobic part essentialy hinders the efficient H bonding between COOH gr and water molecules, resulting in lowest solubility.

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects