Arrange the following sequential steps involved in the laboratory preparation and isolation of soap (saponification) from vegetable oil in the correct chronological order from first to last:
- 1Refluxing the vegetable oil with concentrated sodium hydroxide solution to break the ester linkages.
- 2Adding a concentrated solution of sodium chloride (brine) to the hot reaction mixture.
- 3Filtering the cold mixture to separate the solid crude soap curd from the liquid glycerol filtrate.
- 4Washing the collected solid soap curd with cold distilled water to remove excess alkali.
Cevap
The correct order of steps for the preparation and isolation of soap is: first, refluxing the vegetable oil with concentrated sodium hydroxide (saponification); second, adding concentrated sodium chloride solution (salting out); third, filtering the mixture to separate the solid soap curd; and fourth, washing the solid soap with cold distilled water to remove impurities.
Saponification begins by refluxing vegetable oil (a triglyceride ester) with concentrated sodium hydroxide, hydrolyzing the ester links to yield sodium alkanoates (soap) and glycerol. Next, concentrated sodium chloride solution is added (salting out) to precipitate the soap by decreasing its solubility. The mixture is then filtered to isolate the solid soap curd from the liquid filtrate, and finally, the solid residue is washed with cold distilled water to remove excess sodium hydroxide.
Adım Adım Çözüm
Anahtar Kavram
Saponification process and salting out of soap
Tahmini Süre:1m 30s