PREPARATIONS 157 is that the latter when treated with nitric acid (in the presence of sulphuric acid) undergo direct nitration, benzene being thus converted to nitrobenzene: C 6 H 5 H + HONO 2 ^-C 6 H 5 NO 2 + H 2 O. A similar reaction occurs only very rarely with aliphatic hydrocarbons. It is found experimentally, however, that if benzene is treated with concen-trated nitric acid alone, the yield of nitrobenzene is small. If, however, the nitric acid is first mixed with concentrated sulphuric acid, a high yield of nitrobenzene results. Ingold and co-workers have shown that nitration is caused by the nitronium + + + ion, NO 2 . The overall reaction is: C 6 H 6-f- NO 2 > C 6 H 5 NO 2 + H + It is considered that the NO 1 ion is produced in the mixture of nitric and sulphuric acids by changes such as: + H 8 SO 4 + HNO 3 + HSO 4 + H 2 NO 3 + _ + + H 1 NO 8 + H 2 SO 4 > HSO 4 + H 8 O 4- NO 1 Nitrobenzene. C 6 H 5 NO 2 . Required:
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This note was uploaded on 09/19/2011 for the course CHM 2211 taught by Professor Castalleano during the Fall '06 term at University of Florida.