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13. A compound has a molecular weight of 137 . Which of the following structures is the correct one for the compound? 14. 13C NMR offers better , but poorer than 1H NMR. (4 pts) 15. A compound has molecular formula C8H10 and every mole of this compound is able to react with 3 mole of H2 in a complete catalytic hydrogenation. How many ring(s) is (are) there in this compound? How many -bond(s) is (are) there in this compound? 16. What combination of acyl chloride or acid anhydride and arene would you choose to prepare the following compound by Friedel-Crafts acylation