CHM113_Hydrolysis (Saponification) Rx_Making Soap 4 Lab Experiment I.Soap preparation:You will prepare soap via basic (alkaline) hydrolysis of lard (saponification reaction).When lard is reacted with sodium hydroxide the resultant “soap” is actually a mixture of salts (soaps): sodium oleate (highest %), sodium palmitate, sodium stearate, sodium linoleate (linoleic acid sodium salt), etc. Ethanol is added to the reaction to facilitate the mixing of the fat (melted lard) and the aqueous sodium hydroxide solution while the reaction mixture is refluxed. After refluxing, the reaction mixture is added to a saturated sodium chloride solution in order to precipitate the soap. The saturated sodium chloride solution increases the ionic strength of the aqueous layer and the soap will separate (will “coagulate”). The soap is then filtered and washed to obtain the final product. II.Soap properties:Some properties of the prepared soap will be tested and compared to the same properties of commercial soaps/detergents.Reagents and Materials Lard Sodium hydroxide, pellets Ethanol Sodium chloride, saturated solution Calcium chloride, anhydrous Lab detergent (Alconox) Hand soap (SoftSoap) Vials and/or test tubes Tea impregnated paper towel (our “dirty” paper towel)Safety: Sodium hydroxide is CAUSTIC –handle with care!!! Wear gloves and handle all reagents under the hood. Procedure I. Soap Preparation 1.Add 20 ml distilled water to a 125 ml Erlenmeyer flask 2.Weigh 5.0 g NaOH pellets (in the weighting dish provided) and carefully add it to the flask Notes: (1) avoid splashing!; (2) flask will become hot, handle with care). Swirl until all solid dissolves. Rinse the weighting dish with water and set aside (it will be used later). 3.Weigh 5.0 g lard and add it to the NaOH solution. Once all lard melts transfer this mixture (use a funnel if needed) into the 100 ml RB flask from glass kit. Rinse the Erlenmeyer flask with 20 ml Ethanol (2 washes with ~10 ml each) and transfer to the RB flask. Add a couple boiling chips and gently mix. 4.Clamp the RB flask to a ring stand and set up the reflux apparatus (use the small heating mantle).