8. While study the saponification reaction, what do you observewhen you mix an equal amount of colourless vegetable oil 20%aqueous solution of NaOH in a beaker?(a) The colour of the mixture has become dark brown(b) A brisk effervescence is taking place in the beaker(c) The outer surface of the beaker has become hot(d) The outer surface of the beaker has become cold

8. While study the saponification reaction, what do you observewhen yo

1.	8. While study the saponification reaction, what do you observewhen you mix an equal amount of colourless vegetable oil 20%aqueous solution of NaOH in a beaker?(a) The colour of the mixture has become dark brown(b) A brisk effervescence is taking place in the beaker(c) The outer surface of the beaker has become hot(d) The outer surface of the beaker has become cold
Answer» When you mix vegetable oil with 20% NaOH in ethanol. The alkaline hydrolysis leads to formation of the sodium salt of the fatty acid. Boil this under reflux to speed up the reaction and move it to completion. Reflux stops volatile components from escaping. The ethanol content is removed by distillation. The residue left is excess NaOH, glycerol and soap dissolved in minimum hot water Once cooled, pour it into concentrated NaCl solution. Stir and allow it tocool as well. Glycerol and NaOH dissolve in brine. Soap does not dissolve in brine and forms a cake on top of the liquid. Water, brine and glycerol is removed by a vacuum filtration. Soap is rinsed with ice-cold water to reduced amount, lost by dissolving.