Question

LIQUID-LIQUID EXTRACTION:

What intermolecular interactions are responsible for the decrease in solubility in the aqueous solvent after protonation?
What happens to the compound (solute) after protonation? How does HCl cause a decrease in solubility and ultimately the formation of crystals?

Reaction #1) 2-chlorobenzoic acid is protonated by HCl

Reaction #2) 4-tert-butylphenol is protonated by HCl

Answer 1

Answer:

When protonation happens mass and charge increases by one unit. Since, after protonation the solute becomes charged, Coloumbic force of attraction exists between the molecules. This Coloumbic attraction of force starts to decrease the solubility in the aqueous solvent after protonation. Also the solubility decreases because of common ion effect.

When HCl is added protonation occurs, this results in the decreases the solubility of the solute. The Coloumbic force of attraction that exists between the molecules of the solute force the molecule to form crystals.