what is the purpose of steps 5 and 6

Step One: Benzaldehyde to Benzoin 1. Set up a 60C hot water bath. (Measure temperature with a thermometer and not the hot plate temperature reading) 2. Option one, Crush up seven Vitamin B-1 tablets with mortar and pestle and record the weight to calculate the amount of thiamine hydrochloride being used. Option two: Weigh out 2.0g of thiamine hydrochloride. 3. Add the thiamine hydrochloride to a dry 50mL Erlenmeyer flask. Option One (if the tablets are used): Dissolve the solid in 8.0-10.0 mL of water by swirling, making sure to dissolve the solid as much as possible. (Binders will not dissolve) Option Two (if the powdered thiamine hydrochloride is used): Dissolve the solid in 4.0mL of water by swirling, making sure to dissolve the solid completely. 4. Add 20mL of 95% ethanol and cool the solution for a few minutes in an ice bath. 5. Add 3mL of 5M sodium hydroxide (auto pipet) with swirling to the flask still in the ice bath so that the temperature of the solution never rises above 20C. Note: Color will turn bright yellow. The pH should also be at least 9 or above. 6. To the yellow solution, add 7.0mL of benzaldehyde, a stir bar, and cover flask with Parafilm. Heat the mixture for 2 hours in the water bath (about 6065C ). Caution: The temperature of this reaction cannot go above 65C. Constant monitoring of temperature is crucial \& must be maintained between 6065C. 7. Remove the stir bar and cool the reaction mixture in an ice bath. 8. Collect the product by vacuum filtration and wash it with a 1:1 mixture of 95% ethanol and water. 5. Recrystallize the crude product using hot 95% ethanol. Once your pure product has been obtained, dry it thoroughly before continuing on (if time is limited, dry overnight and continue on day 2 of experiment). The product should be colorless. 10. Weigh your purified product, record its mass, \& test the melting point (MP Benzoin is 135C )