Circle true or false regarding the following statements about the labs you have done ( 5 points each): 1. The pH value should be adjusted higher than 9 for the synthesis of Benzoin from benzaldehyde. 2. The copper acetate was used as an oxidant for the synthesis of benzil. TrueTrueFalse Multiple Choice Questions, please circle the correct answer (5 points each): 3. Why did you use NaBH4 in the synthesis of hydrobenzoin from benzil? A. Drying agent. B. Oxidant. C. Reactant. D. All of the above 4. What intermediate (active species) was generated when you used the thiamine in the synthesis of benzoin from benzaldehyde? A. Carbene. B. Cation. C. Anion. D. Free radical. Answer the following questions ( 5 points each): 5. How could you know which isomers of hydrobenzoin you got in the reduction lab? 6. Why could you see the compounds on F254 TLC plate under the UV light? 7. Which compound among benzil, benzoin and hydrobenzoin should have the largest Rtvalue?Draw the structures and give the explanation? 8. If the yield of reaction 1 is 50% and reaction 2 is 60%, calculate the total percent yield of the two steps reaction. Benzoin m.......... Benzil ........... hydrobenzoin