By using benzoin, ethanol, sodium borohydride, water, 6M HCL, and acetone the goal was to recover as much crystals back which 68.5 % was obtained. Benzoin (0.5g), ethanol (4mL) was used at first into a flask (25mL). Adding sodium borohydride (0.1g) and swirling it for 20 minutes made the benzoin very white. Adding water (7.5mL) and 6M HCl (0.3mL) then vacuum filtrating made the substance to come together as one big chunk. Using acetone, it was recrystallized. Then two TLC plates were used. On the left was starting benzoin for both plates. On the right was recrystallized one for the first one but the second one had the crude one. The middle had both of it contained. Running the TLC plates was the next step and by using the chamber and after it had dried the UV light was used to mark the spots. Desired reaction product will go all the way to the top without separating instead of staying down low when the TLC plate is used. There were total of 4 spots including the starting material. Benzoin had one spot, recrystallized in the first plate had 1 spot as well as for crude. The middle however that contained both the starting benzoin and either recrystallized or crude had 2 different spots. Instead of water, what if acetone was used? Acetone can dry up a substance quicker than water so by using acetone instead of water in the reaction equation, maybe it would have been more accurate and faster. Also, by using less amount of each substance, time could have been saved and it could be a possible modification needed for this lab. There is a double bond on the oxygen in the first equation, but by taking away the double bond, the hydrogen gets added to the oxygen in the final reaction. There were many times in this lab where waiting and swirling for a long time occurred, so by cutting down the amount would do a better faster job.
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