Question

Heya am confused on how they do this, like do they add the molar mass of nitric acid to the molar mass of the benzene group?

1. Treatment of benzene with an excess of nitric acid and sulfuric acid led to the formation of a yellow solid. A mass spectrum of this material showed a molecular ion at m/z = 168. How many nitro groups were present in the product? HNO3 H2SO4 Two. Benzene has a MW of 78. Mononitration would lead to a product with a MW of 123. A MW of 168 corresponds to a dinitration.

Answer 1

NO2 Mono Nitration : + 401 323-343 + HNO3 + H, 50, 333-3435 D Benzene (C6H6) (MW =18 T + HNO₃ + H₂SO4 Nitro Benzene (C6H5 NO2). . (Mw=123) → HNO3 + H, 50%=Not+ HSO4 + Mgo > molecular mass of Benzene? 646 = 6(mass of c atom) + 6 (mass of H-atom) 6 (12 u) + 6(1u) - 72 +6 CO H6 = 78 (AWD molecular mass of nitrobenzene: 3 C6Hg No2 = 6 (mass of c-atom) + 5 (mass off H-atom) + 1 (mass of N-atom) +2(mass of orator) A . = 6 (22 u) +5 (10)+1(14 W) + 2(162) =7245 +14+ 32 u C6H5NoR = 123 (MW) ® Dinitration : - HNO, TH2504 Howey / M504_, O ANO - H20 - Nitro Benzene (C6H5NO2) Mo=123 Di Nitro Benzene (C6H4N204)

-> Nitro Benzene (mw=123) in is a meta directing group React with H₂SOL PHNO and Benzene (mw=168 gr/mod) enzene (MW=123) in directing group - Pasou I kno, and a Nitro group so, Nitrobenzene produced m-dinitro- a so. pro No 7 molecular mass of Dinitro Benzene: EGHAN2O4 = 6 (mars of c) th (mass of H) + +4 (mass of o) 56 (12) + 4 (1) +2(14) +4616) = 168 g/mole mw)