Notebook. This experiment involves a chemical preparation so you should set up your notebook according to the examples given in Padias and How to Keep a Lab Notebook.
Your chemical equation should not be a mechanism. Rather, show the material you will start with (methyl salicylate), important reagents (NaOH and H2O), important conditions ("reflux"), and the product that you expect to get (salicylic acid). Do not draw anything else.
Don't forget to include a table of physical properties for the substances that might appear in this experiment. This includes all starting materials, reagents, and product. A sample table with "?" indicating vital information is shown below.
Safety & Disposal. Wear gloves and goggles and carry out all operations in a fume hood. These are standard operating procedures, but they are especially important in this experiment. Any other hazards and warnings about safe handling should be entered in your notebook. Disposal procedures should also be entered for each reagent. Salicylic acid will be collected in a special container.
Online videos. Please review the following videos on lab procedures before lab (these are all from The Interactive Lab Primer):
In your fume hood: place a stirring motor on top of a partially opened lab jack, then place a heater on top of the motor. Clamp the round bottom flask to the monkey bars in your fume hood so that it rests in the heater . Plug the heater into the controller, but do not turn on the controller (never plug a heater directly into a wall socket).
Transfer about 21 mmol of methyl salicylate to your graduated cylinder [NOTE 4].]. Record the volume that you actually use and transfer this material to the round bottom flask using a funnel. You should see a white gummy material form in your flask [
Equip the flask with a stir bar, reflux condenser, and water hoses . Slowly flow water through the reflux condenser and adjust the controller voltage to initiate reflux . Reflux the mixture for 30 minutes, while stirring as best you can (the gummy material prevents the stir bar from working at first, but the material soon dissolves). Turn off the controller and remove the lab jack, motor, and heater. Allow the mixture to cool to room temperature before continuing .
Place your crude salicylic acid and 5-10 mL of deionized water in a 250 mL Erlenmeyer flask ("acid" flask). Place about 80-120 mL of deionized water in a second flask ("water" flask). Add 2-3 boiling chips to each flask. Place the "water" flask on a hot plate and bring the water to a boil. Next, set the "acid" flask next to the "water" flask on the hot plate and bring the "acid" mixture to a boil as well. Transfer just enough boiling water from the "water" flask to the "acid" flask to dissolve all of the solids in the "acid" flask . Remove the "acid" flask FROM THE hot plate and let the solution cool slowly. Salicylic acid should crystallize spontaneously.
After the solution has cooled sufficiently, recover the product by vacuum filtration (use a clean filter flask and funnel). Set the product on a watch glass inside your laboratory cabinet to dry.
Characterization (Week 2)
After your product has dried for at least 12 hours, record its weight and its melting temperature [NOTE 13].