31.

C₆H₅-NO₂ $\underset{\mathrm{NHCl}}{\overset{\mathrm{Zn}-\mathrm{dust}}{\to }}$ A $\underset{\mathrm{conc}. \mathrm{HCl}}{\overset{\mathrm{cold}}{\to }}$ B 

A and B respectively are

• 

• 

• 

• None of the above

In keto-enol tautomerism of dicarbonyl compounds, the enol-form is preferred in contrast to the keto-form, this is due to

• presence of carbonyl group on each side of -CH₂ group

• resonance stabilisation of enol form

• presence of methylene group

• rapid chemical exchange

Which of the following sets of reactants is used for preparation of paracetamol from phenol?

• HNO₃, H₂/ Pd(CH₃CO)₂O

• H₂SO₄, H₂/ Pd (CH₃CO)₂ O

• C₆H₅N₂Cl, SnCl₂/ HCl (CH₃CO)₂O

• Br₂/ H₂O, Zn/ HCl (CH₃CO)₂O

A certain compound gives negative test with ninhydrin and positive test with Benedict's solution. The compound is

• a protein

• a monosaccharide

• a lipid

• an amino acid

Super glue or crazy glue is

• poly (methyl methacrylate)

• poly (ethyl acrylate)

• poly (methyl -cyanoacrylate)

• poly (ethyl methacrylate)

X and Y in the above given reaction are

• picric acid, 2,4, 6-tribromophenol

• 5-nitrophenol acid, 5-bromosalicylic acid

• o-nitrophenol, o-bromophenol

• 3, 5-dinitrosalicylic acid, 3,5-dibromosalicylic acid

In the cannizzaro reaction given below, the slowest step is

2Ph - CHO $\stackrel{{\mathrm{OH}}^{-}}{\to }$ Ph - CH₂ - OH + PhCO${}_2^{-}$

• the attack of OH^- at the carbonyl group

• the transfer of hydride ion to the carbonyl group

• the abstraction of a proton from the carboxylic acid

• the deprotonation of Ph - CH₂OH

The reaction of 1-bromo-3-chlorocyclobutane with metallic sodium in dioxane under reflux conditions gives

Identify Z in the following reaction sequence

CH₃CH₂CH₂OH $\underset{160-180°\mathrm{C}}{\overset{\mathrm{Conce}. {\mathrm{H}}_2{\mathrm{SO}}_4}{\to }}$ X → Y $\underset{\left(\mathrm{ii}\right) {\mathrm{NaNH}}_2}{\overset{\left(\mathrm{i}\right) \mathrm{Alc}. \mathrm{KOH}}{\to }}$

• CH₃-CH(NH₂)-CN₂NH₂

• CH₃-CHOH-CH₂OH

• CH₃-C(OH)=CH₂

• CH₃-C≡CH

Which of the following reactions is used to prepare isobutane?

• Wurtz reaction of C₂H₅Br

• Hydrolysis of n-butylmagnesium iodide

• Reduction of propanol with red phosphorus and HI

• Decarboxylation of 3-methylbutanoic acid