Jove Lab Chem

Hydrolysis of an Ester — Lab Prep

Source: Lara Al Hariri at the University of Massachusetts Amherst, MA, USA

1. Preparation of LaboratoryExpand

   Here, we show the laboratory preparation for 10 students working in pairs, with some excess. Please adjust quantities as needed.

   • Before you get started, put on a lab coat, safety glasses, and nitrile gloves. Ensure that the lab is equipped with enough lab coats, splash goggles, and gloves for all of the students.
   • Prepare 1 L of 3 M NaOH. Measure 120 g of NaOH pellets, and transfer the pellets to a 1-L volumetric flask. Add deionized water to the 1-L line. Place a stir bar in the flask and mix the solution until the pellets are fully dissolved.
   • Once the solution is homogeneous, transfer the solution to a glass bottle, cap it, and label it. Place the bottle in a central hood so that students have access to it.
   • Prepare 1 L of 1 M CaCl₂ solution. Weigh 110.98 g of CaCl₂, and transfer it to a 1-L volumetric flask. Fill the flask to the marked line with deionized water, add a stir bar, and mix the solution on a stir plate until the CaCl₂ is fully dissolved.
   • Once the solution is homogeneous, transfer it to a clean glass bottle, cap it, and label it. Store the solution in a central hood.
   • Prepare at least 1 L of 3 M HCl, which will be used to neutralize any excess sodium hydroxide at the end of the experiment.
   • Obtain 5 silicone soap molds and leave them in a common area. Obtain at least five different fragrance oils and five powder soap dyes in a variety of colors, and set them near the molds.
   • Place a container of commercial liquid soap in a common area. Set coconut oil next to the balance making sure there are clean spatulas and weighing boats.
   • Set out the following glassware and equipment at each student lab station (we suggest that students work in pairs):

     1    Stir bar

     1    Hotplate

     1    Package of pH paper

     1    pH meter

     1    250-mL plastic squeeze bottle of DI water

     2    50-mL volumetric flasks

     2    100-mL glass graduated cylinders

     6    50-mL glass graduated cylinders

     1    50-mL beaker

     2    400-mL beaker

     2    Glass vials

     1    Glass stirring rod

     1    Small spoon

     1    Small spatula