Make sure that the procedure you have written in your lab notebook pages reflects the following modifications:
Each of you will be assigned to one of the four unique solvent-starting material combinations. Your assigned combination appears only in Part I or Part II of the procedure as written in the textbook; you do not need to copy down the procedure or record observations for parts you were not assigned, but you will need the final results (melting point, TLC, etc.) for all four possibilities.
In the interest of good science, every solvent-starting material combination will be approached as consistently as possible. This means that all four iterations will...
...use 0.35 mmol of the benzil or benzoin starting material.
...use 0.5 mL of the isopropanol, ethanol, or methanol solvent.
...cool the initial benzil or benzoin solutions in an ice water bath.
...use 15 mg of sodium borohydride reducing agent.
...track the reaction using TLC at a minimum of six time points: 0, 2, 5, 10, 12, and 15 minutes.
...add 1.0 mL of water to the finished reaction to start recrystallization.
...measure three melting points: the pure product, the product mixed with benzoin, and the product mixed with the product of a different solvent-starting material combination.