Preparation of Synthetic Banana Oil (Isopentyl Acetate)

Isolation of Chlorophyll and Carotenoid Pigment from Starch

Assigned Questions

2. Why is the mixture extracted with sodium bicarbonate? Give an equation and explain its relevance.

- Sodium bicarbonate is preferable for this extraction because it will react with any unreacted or residual acid in the mixture to form neutralized solution. The ester, which is water insoluble, would separate from the neutralized acid because it is water soluble. This will increase the purity of the end product. The esterification process cannot be reversed with sodium bicarbonate because it is a weak base. As a result, it can remove the carboxylic acid and sulfuric acid catalysts that have not been reacted.

The equation is R-CO-H-->R-CO-(COO-) because the esters are released from the molecule as carbon dioxide and water.

3. Why are gas bubbles observed when the sodium bicarbonate is added?

- The reaction of the sodium bicarbonate with the acid emits Carbon dioxide gas, which is observed as gas bubbles.

Which reagent is used o the reaction

4. Which starting material is the limiting reagent in this procedure? Which reagent in excess? How great is the molar excess (how many times greater)?

- The isopentyl alcohol is the limiting reagent while acetic acid is the excess reagent. The molar excess is about 1.5 – 1.75 times more than the amount theoretically produced.

5. Outline a separation scheme for isolating pure isopentyl acetate from the ro mixture.

- The crude product is washed with 10 ml of water before being transferred to a separatory funnel. When the solution forms two layers, the bottom aqueous layer is discarded. After that, the answer is blended with 5 ml portions of 5% sodium bicarbonate until distinct layers emerge; the bottom layer is then drained off. 5 ml portions of 5% sodium bicarbonate are fed continually until the aqueous layer’s pH becomes basic.