SOLVED

31) Which of the following could be added across carbon-carbon multiple bonds? I) H2SO4 II) H2 III) H2O IV) NO2 V) HBr A) II), III), and V) B) II), III), and IV) C) I), III), and V) D) I), III), and IV) E) I), II), and III) 32) From the following table select appropriate starting material and reagents required for the synthesis of 2-methyl-2-propanol (tert-butanol): Starting materials:Reagents A)I) H2/Pt B)II) H2O/ H2SO4 C)III) HBr A) Starting material B) and reactants II) B) Starting material C) and reactants I) C) Starting material A) and reactants II) D) Starting material A) and reactants III) E) Starting material B) and reactants I) 33) Which of the following steps would you expect to occur in the addition reaction mechanism? I) Electrophilic attack on the unsaturated bond II) Formation of carboanion III) Formation of carbocation IV) Nucleophilic attack on the carbocation V) Elimination of a base A) I), III), and IV) B) I), II), and V) C) II), III) and IV) D) III), IV) and V) E) II), IV) and V) 34) A hydrocarbon has a molecular weight 56 g/mol and contains 85.7% carbon. It easily adds one mol of HBr to produce a chiral alkyl bromide. Which of the following structures could be our hydrocarbon? A) B) C) D) E) 35) Which of the following groups is a meta director during electrophilic aromatic substitution? A) -NH2 B) -OCH3 C) -Br D) -C≡N E) -OCOC2H5 36) Find a group that is a ortho,para director in electrophilic aromatic substitution. A) -NO2 B) -SO3H C) -OH D) -COH E) -COOCH3 37) What is arenium ion? A) a carbocation formed after the electrophilic attack on the benzene ring B) a carbocation formed from a molecule containing an arene ring C) a carbocation formed during the elimination reaction from an aromatic molecule D) a carboanion formed from deprotonation of benzene ring E) a carboanion formed after nucleophilic attack on the benzene ring 38) During the nitration of a benzene ring in a mixture of HNO3 and H2SO4 the following species reacts as an electrophile: A) H3O+ B) H3SO4+ C) H2NO3+ D) H+ E) NO2+ 39) Which of the following compounds could be used as catalysts in halogenation of benzene? I) AlCl3 II) NaCl III) FeBr3 IV) MgCl2 V) PbCl2 A) I) and V) B) II) and III) C) II) and IV) D) I) and III) E) III) and V) 40) Which of the following mechanistic steps do you expect in bromination of benzene with Br2 and FeBr3 as a catalyst? I) Formation of Br+[FeBr4]- II) Attack of [FeBr4]- on benzene ring III) Formation of arenium ion IV) Deprotonation of arenium ion V) Nucleophilic attack of Br+ A) I), III), and IV) B) I), II), and IV) C) II), III), and V) D) III), IV), and V) E) II), IV), and V)