EAS Exercises

1. The o:p ratio in the mononitration of bromobenzene has been reported to be 38:62. Using this ratio and the amount of 4-nitrobromobenzene you obtained, calculate the experimental yield of your reaction?

2. Why is the bromobenzene added in portions over a 15-min period rather than all at once ?

3. Explain why 4-nitrobromobenzene predominates in the product mixture.

4. Why is dinitration not a significant process under the conditions used ?

5. What is the function of the concentrated sulfuric acid in this experiment ?

6. Why is the reaction flask shaken frequently during the addition of the bromobenzene to the acid mixture?

7. Is the nitration reaction exothermic or endothermic ?

8. What compounds are present in the aqueous solution from which the bromobenzene isomers are filtered?

9. Why is the p-isomer of the product less soluble in ethanol than the o-isomer ?

10. Explain the theory of TLC.