Pick one of the derivatives and state how to purify the product. Carboxylic acid
ID: 501579 • Letter: P
Question
Pick one of the derivatives and state how to purify the product. Carboxylic acid derivatives (in which a carbon has a valence of +3) may be hydrolyzed to the acid by reacting them with aqueous acid or base. The base offers the advantage of indicating completion of the reaction by total solubility of the product in the base solution. Seventy five mL of 4M NaOH will suffice to hydrolyze 0.025 moles of any derivative although the temperature required will differ markedly. In the absence of specific knowledge, the derivative should be added carefully to the cold base in an apparatus which will allow for subsequent refluxing if it appears necessary. Purification of the product should be based upon its acidic properties. Choose any one of the above listed benzoic acid derivatives. Complete a pre-lab sheet which specifies the derivative you plan to hydrolyze and how you plan to purify your product.Explanation / Answer
Hydrolysis of ester to carboxylic acid using NaOH as the base in water
To a clean dry flask take your weighed diester compound. to this add, required amount of aqueous NaOH solution.
Heat the solution to complete the reaction. The reaction mixture is stirred throughout the experiment. Once the hydrolysis is complete, cool the reaction to room temperature. Add concentrated HCl to the mixture to precipitate the carboxylic acid formed. Filter the carboxylic acid compound and wash with cold water.
The product is redissolved in a proper organic solvent in which it is mildly soluble at room temperaturw but completely soluble at higher temperature. Dissolve the compound, filter the solution when hot to remove undissolved impurities. Let it cool and stand at room temperature. Solid crystals will start forming. once all the crystallization is done, filter the solid. Discard the filtrate. Dry the product and fully characterize it.