Answer:
One reason for the precipitation is the formation of insoluble crystals or complexes between the derivatives and the carbonyl compounds. The reaction between 2,4-DNP or semicarbazone derivatives and carbonyl compounds involves the formation of stable imine or hydrazone derivatives. These derivatives have lower solubility in ethanol compared to the original derivatives. As a result, they tend to form solid precipitates or crystals that separate out from the solution.
Step-by-step explanation:
When 2,4-DNP or semicarbazone derivatives react with carbonyl compounds, they undergo a chemical reaction to form stable imine or hydrazone derivatives. These derivatives have a lower solubility in ethanol compared to the original derivatives. As a result, they tend to come together and form insoluble crystals or complexes.The formation of these insoluble crystals or complexes is due to the intermolecular forces present in the system. The imine or hydrazone derivatives have specific structural features that allow them to interact with each other or with the carbonyl compounds through various intermolecular forces such as hydrogen bonding or van der Waals forces. These interactions lead to the aggregation of molecules, resulting in the formation of solid precipitates or crystals.Since the solubility of these derivatives is lower in ethanol, the solvent cannot effectively disperse or dissolve the formed crystals or complexes. Instead, they separate out from the solution and become visible as a precipitate.Overall, the formation of insoluble crystals or complexes between the 2,4-DNP or semicarbazone derivatives and carbonyl compounds, along with their decreased solubility in ethanol, leads to the precipitation of these derivatives from ethanolic solutions.
Hope this helped